-
摘要: 以石墨烯为代表的二维材料因其独特的结构和优异性能而受到广泛关注。随着二维材料在无限小的方向不断发展,二维(材料)量子片逐渐引起人们极大的兴趣。二维量子片不仅保留了二维材料的本征特性,而且表现出量子限域和突出的边缘效应,为二维材料的潜在应用带来全新机遇。本文详细介绍了二维量子片的基本概念,制备现状与光学性能的研究进展,特别强调了二维量子片本征、普适和规模制备的实现及其重大意义。此外,重点关注了二维量子片的光致发光特性以及在非线性光学、固态发光器件等领域的应用。最后,分析了二维量子片的发展趋势以及面临的主要挑战。Abstract: Two-dimensional (2D) materials like graphene have attracted much attention due to their unique structures and exotic properties. With significantly reduced lateral sizes, 2D quantum sheets (2D QSs) are attracting an increasing level of interest. 2D QSs have opportunities for new applications because of their intrinsic characteristics of being 2D materials and having emerging quantum confinement and prominent edge effects. This review focuses on the conceptual interpretation of 2D QSs and the recent progress on their preparation and optical properties. Particular focus is given to the realization and significance of the universal and scalable production of intrinsic 2D QSs. In addition, the photoluminescence of 2D QSs and their applications in nonlinear optics and solid-state light-emitting devices are reviewed. At the end, the perspectives and challenges towards the future development of 2D QSs are discussed.
-
Key words:
- two-dimensional materials /
- quantum sheets /
- photoluminescence /
- nonlinear optics
-
图 1 (a)量子片所处体系的示意图[31];(b)二维量子片的文章发表数目(2007—2016)[4];(c)二维量子片的应用领域:医药[24],生物成像[25],催化[26],太阳能电池[27],非线性光学[28]等。(b)转载自文献[4],版权所有(2018)皇家化学学会。(c) 转载自文献[24],版权所有(2018)施普林格;转载自文献[25],版权所有(2018)施普林格;转载自文献[26],版权所有(2016)自然出版集团;转载自文献[27],版权所有(2018)施普林格;转载自文献[28],版权所有(2020)美国化学学会
Figure 1. (a) Schematic diagram of the system in which the quantum sheet is located[31];(b) number of journal publications on 2D QSs from 2007 to 2016[4];(c) application fields of 2D QSs:medicine[24], biological imaging[25],catalysis[26],solar cell[27],nonlinear optics[28],etc. (b) Adapted with permission ref. [4]. Copyright 2018, Royal Society of Chemistry; (c) Reproduced with permission ref. [24]. Copyright 2018, Springer. Reproduced with permission ref. [25]. Copyright 2018, Springer; Reproduced with permission ref. [26]. Copyright 2016, Nature Publishing Group; Reproduced with permission ref. [27]. Copyright 2018, Springer; Reproduced with permission ref. [28]. Copyright 2020, American Chemical Society.
图 2 二维材料的原子结构。(a)石墨烯[3];(b)氮化硼[3];(c)二硫化钼[48];(d)硒化铟[49];(e)氮化碳[50];(f)黑磷[41]。(a) 和(b)转载自文献[3],版权所有(2017)美国化学学会;(c) 转载自文献[48],版权所有(2011)自然出版集团;(d) 转载自文献[49],版权所有(2017)自然出版集团;(e) 转载自文献[50],版权所有(2017)皇家化学学会;(f) 转载自文献[41],版权所有(2014)自然出版集团
Figure 2. Atomic structures of 2D materials. (a) Graphene[3]; (b) BN[3]; (c) MoS2[48]; (d) InSe[49]; (e) C3N4[50]; (f) BP[41]. (a) and (b) Adapted with permission ref. [3]. Copyright 2017, American Chemical Society. (c) Adapted with permission ref. [48]. Copyright 2011, Nature Publishing Group. (d) Adapted with permission ref. [49]. Copyright 2017, Nature Publishing Group. (e) Adapted with permission ref. [50]. Copyright 2017, Royal Society of Chemistry. (f) Adapted with permission ref. [41]. Copyright 2014, Nature Publishing Group.
图 3 二维量子片的制备方法。自下而上:(a)化学气相沉积[66];(b)湿化学法[35]。自上而下:(c)电化学剥离[54];(d)研磨结合超声剥离[62];(e)液氮预处理和超声剥离[57];(f)回流预处理和超声剥离[63];(g)超薄切片结合液相剥离[59]。(a) 转载自文献[66],版权所有(2016)美国化学学会;(b)转载自文献[35],版权所有(2019)自然出版集团;(c) 转载自文献[54],版权所有(2015)皇家化学学会。(d) 转载自文献[62],版权所有(2015)威立出版集团;(e)转载自文献[57],版权所有(2017)美国科学促进会;(f)转载自文献[63],版权所有(2019)爱思唯尔;(g)转载自文献[59],版权所有(2020)施普林格
Figure 3. The preparation methods of 2D QSs. Bottom-up: (a) CVD [66]; (b) wet chemical method[35]. Top-down: (c) electrochemical exfoliation[54]; (d) grinding combined with sonication exfoliation[62]; (e) liquid nitrogen pretreatment combined with sonication exfoliation[57]; (f) reflux pretreatment combined with sonication exfoliation[63]; (g) ultrathin section combined with liquid phase dissection[59]. (a) Reproduced with permission ref. [66]. Copyright 2016, American Chemical Society; (b) adapted with permission ref. [35]. Copyright 2019, Nature Publishing Group; (c) reproduced with permission ref. [54]. Copyright 2015, Royal Society of Chemistry; (d) reproduced with permission ref. [62]. Copyright 2015, Wiley-VCH; (e) reproduced with permission ref. [57]. Copyright 2017, AAAS; (f) adapted with permission ref. [63]. Copyright 2019, Elsevier; (g) reproduced with permission ref. [59]. Copyright 2020, Springer.
图 4 二维量子片的本征、普适和规模制备。(a)盐辅助球磨和超声辅助溶剂剥离[60];(b)量子片的制备机理示意图[60];(c)硅球辅助球磨和超声辅助溶剂剥离[23];(d)量子片分散液和粉体照片及对应的高分辨透射电镜照片[23];(e)从多壁碳纳米管制备石墨烯量子片[64]。(a-b)转载自文献[60],版权所有(2017)美国化学学会;(c-d)转载自文献[23],版权所有(2019)皇家化学学会;(e)转载自文献[64],版权所有(2020)美国化学学会
Figure 4. Universal and scalable production of intrinsic 2D QSs. (a) Salt-assisted ball-milling and sonication-assisted solvent exfoliation[60]; (b) schematic diagram of the fabrication mechanism of 2D QSs[60]; (c) silica-assisted ball-milling and sonication-assisted solvent exfoliation[23]; (d) photographs of the QS dispersions and powders and their HRTEM images; (e) robust strategy for tailoring multi-walled carbon nanotubes into GQSs[64]. (a-b) Reproduced with permission ref. [60]. Copyright 2017, American Chemical Society; (c-d) Reproduced with permission ref. [23]. Copyright 2019, Royal Society of Chemistry; (e) Reproduced with permission ref. [64]. Copyright 2020, American Chemical Society.
图 5 二维量子片的光致发光性能。(a)发射波长(nm)对GQSs尺寸的依赖关系[74];(b)不同尺寸石墨烯量子片的颜色变化[75];(c)元素掺杂的影响[80];(d-f)激发波长依赖性[23];(g)浓度依赖性[23];(h)溶剂依赖性[23];(i)固态荧光性能[23]。 (a) 转载自文献[74],版权所有(2015)皇家化学学会;(b) 转载自文献[75],版权所有(2014)美国化学学会;(c) 转载自文献[80],版权所有(2014)威立出版集团;(d-i)转载自文献[23],版权所有(2019)皇家化学学会
Figure 5. Photoluminescence of 2D QSs. (a) Dependence of emission wavelength (nm) on the size of GQSs[74]; (b) color changes of GQSs with different sizes[75]; (c) effects of elemental doping[80]; (d-f) excitation wavelength dependence[23]; (g) concentration dependence[23]; (h) solvent dependence[23]; (i) solid-state fluorescence[23]. (a) Reproduced with permission ref. [74]. Copyright 2015, Royal Society of Chemistry. (b) Adapted with permission ref. [75]. Copyright 2014, American Chemical Society. (c) Reproduced with permission ref. [80]. Copyright 2014, Wiley-VCH. (d-i) Reproduced with permission ref. [23]. Copyright 2019, Royal Society of Chemistry.
图 6 二维量子片在非线性光学中的应用。(a)等离激元增强石墨烯量子片二阶非线性效应[89];(b)黑磷量子片的三阶非线性效应[94];(c)锑烯量子片的光学克尔效应[96];(d)N掺杂的石墨烯量子片的非线性生物成像[87];(e)量子片-PMMA复合薄膜的非线性饱和吸收性能[23]。(a) 转载自文献[89],版权所有(2015)美国化学学会;(b)转载自文献[94],版权所有(2016)威立出版集团;(c) 转载自文献[96],版权所有(2017)威立出版集团;(d)转载自文献[87],版权所有(2013)美国化学学会;(e)转载自文献[23],版权所有(2019)皇家化学学会
Figure 6. Application of 2D QSs in nonlinear optics.(a)Plasmon-enhanced GQSs second-order nonlinearity[89];(b)third-order nonlinearity of BPQSs[94];(c)Kerr effect of AQSs[96];(d)nonlinear biological imaging of N-GQSs[87];(e)nonlinear saturation absorption of QSs-PMMA hybrid films[23]. (a) Reproduced with permission ref. [89]. Copyright 2015, American Chemical Society. (b) Reproduced with permission ref. [94]. Copyright 2016, Wiley-VCH. (c) Reproduced with permission ref. [96]. Copyright 2017, Wiley-VCH.(d)Reproduced with permission ref. [87]. Copyright 2013, American Chemical Society.(e)Reproduced with permission ref. [23]. Copyright 2019, Royal Society of Chemistry.
图 7 二维量子片在固态发光器件中的应用情况。(a)基于GQSs的垂直腔面发射激光器[104];(b)基于V2C MXene量子片的白色激光器[110];(c)基于MoS2 QSs的可拉伸和宽带无腔激光器[106];(d)基于MoS2 QSs(组氨酸掺杂)的白色发光二极管[112]。(a) 转载自文献[104],版权所有(2019)美国化学学会;(b) 转载自文献[110],版权所有(2019)威立出版集团;(c) 转载自文献[106],版权所有(2020)威立出版集团; (d) 转载自文献[112],版权所有(2019)威立出版集团
Figure 7. Applications of 2D QSs in solid-state light emitting device. (a) Vertical cavity surface-emitting lasers based on GQSs[104];(b)white lasers with V2C MXene quantum sheets (MQSs)[110]; (c) stretchable and broadband cavity-free laser devices based on MoS2 QSs[106]; (d) white-light-emitting diodes based on histidine-doped MoS2 QSs[112]. (a) Reproduced with permission ref. [104]. Copyright 2019, American Chemical Society. (b) Reproduced with permission ref. [110]. Copyright 2019, Wiley-VCH. (c) Reproduced with permission ref. [106]. Copyright 2020, Wiley-VCH. (d) Reproduced with permission ref. [112]. Copyright 2019, Wiley-VCH.
-
[1] NOVOSELOV K S, GEIM A K, MOROZOV S V, et al. Electric field effect in atomically thin carbon films[J]. Science, 2004, 306(5696): 666-669. doi: 10.1126/science.1102896 [2] ANASORI B, LUKATSKAYA M R, GOGOTSI Y. 2D metal carbides and nitrides (MXenes) for energy storage[J]. Nature Reviews Materials, 2017, 2(2): 16098. doi: 10.1038/natrevmats.2016.98 [3] TAN CH L, CAO X H, WU X J, et al. Recent advances in ultrathin two-dimensional nanomaterials[J]. Chemical Reviews, 2017, 117(9): 6225-6331. doi: 10.1021/acs.chemrev.6b00558 [4] XU Y H, WANG X X, ZHANG W L, et al. Recent progress in two-dimensional inorganic quantum dots[J]. Chemical Society Reviews, 2018, 47(2): 586-625. doi: 10.1039/C7CS00500H [5] ASHTON M, PAUL J, SINNOTT S B, et al. Topology-scaling identification of layered solids and stable exfoliated 2D materials[J]. Physical Review Letters, 2017, 118(10): 106101. doi: 10.1103/PhysRevLett.118.106101 [6] WANG X M, JONES A M, SEYLER K L, et al. Highly anisotropic and robust excitons in monolayer black phosphorus[J]. Nature Nanotechnology, 2015, 10(6): 517-521. doi: 10.1038/nnano.2015.71 [7] TAN CH L, ZHANG H. Two-dimensional transition metal dichalcogenide nanosheet-based composites[J]. Chemical Society Reviews, 2015, 44(9): 2713-2731. doi: 10.1039/C4CS00182F [8] NOVOSELOV K S, MISHCHENKO A, CARVALHO A, et al. 2D materials and van der Waals heterostructures[J]. Science, 2016, 353(6298): aac9439. [9] LIU Y, WEISS N O, DUAN X D, et al. Van der Waals heterostructures and devices[J]. Nature Reviews Materials, 2016, 1(9): 16042. [10] HUANG B, CLARK G, NAVARRO-MORATALLA E, et al. Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit[J]. Nature, 2017, 546(7657): 270-273. doi: 10.1038/nature22391 [11] CAO Y, FATEMI V, FANG S A, et al. Unconventional superconductivity in magic-angle graphene superlattices[J]. Nature, 2018, 556(7699): 43-50. doi: 10.1038/nature26160 [12] BONACCORSO F, COLOMBO L, YU G H, et al. Graphene, related two-dimensional crystals, and hybrid systems for energy conversion and storage[J]. Science, 2015, 347(6217): 1246501. doi: 10.1126/science.1246501 [13] BHIMANAPATI G R, LIN ZH, MEUNIER V, et al. Recent advances in two-dimensional materials beyond graphene[J]. ACS Nano, 2015, 9(12): 11509-11539. doi: 10.1021/acsnano.5b05556 [14] ZHU F F, CHEN W J, XU Y, et al. Epitaxial growth of two-dimensional stanene[J]. Nature Materials, 2015, 14(10): 1020-1025. doi: 10.1038/nmat4384 [15] DONG R H, ZHANG T, FENG X L. Interface-assisted synthesis of 2D materials: trend and challenges[J]. Chemical Reviews, 2018, 118(13): 6189-6235. doi: 10.1021/acs.chemrev.8b00056 [16] LEE Y H, ZHANG X Q, ZHANG W J, et al. Synthesis of large-area MoS2 atomic layers with chemical vapor deposition[J]. Advanced Materials, 2012, 24(17): 2320-2325. doi: 10.1002/adma.201104798 [17] PENG D, ZHANG L, LI F F, et al. Facile and green approach to the synthesis of boron nitride quantum dots for 2, 4, 6-trinitrophenol sensing[J]. ACS Applied Materials &Interfaces, 2018, 10(8): 7315-7323. [18] NAJAFI L, TAHERI B, MARTíN-GARCÍA B, et al. MoS2 quantum dot/graphene hybrids for advanced interface engineering of a CH3NH3PbI3 perovskite solar cell with an efficiency of over 20%[J]. ACS Nano, 2018, 12(11): 10736-10754. doi: 10.1021/acsnano.8b05514 [19] YONG Y, CHENG X J, BAO T, et al. Tungsten sulfide quantum dots as multifunctional nanotheranostics for in vivo dual-modal image-guided photothermal/radiotherapy synergistic therapy[J]. ACS Nano, 2015, 9(12): 12451-12463. doi: 10.1021/acsnano.5b05825 [20] HA H D, HAN D J, CHOI J S, et al. Dual role of blue luminescent MoS2 quantum dots in fluorescence resonance energy transfer phenomenon[J]. Small, 2014, 10(19): 3858-3862. doi: 10.1002/smll.201400988 [21] ZHOU J B, LIN J H, HUANG X W, et al. A library of atomically thin metal chalcogenides[J]. Nature, 2018, 556(7701): 355-359. doi: 10.1038/s41586-018-0008-3 [22] WANG L, XU X Z, ZHANG L N, et al. Epitaxial growth of a 100-square-centimetre single-crystal hexagonal boron nitride monolayer on copper[J]. Nature, 2019, 570(7759): 91-95. doi: 10.1038/s41586-019-1226-z [23] XU Y Q, CHEN SH L, DOU ZH P, et al. Robust production of 2D quantum sheets from bulk layered materials[J]. Materials Horizons, 2019, 6(7): 1416-1424. doi: 10.1039/C9MH00272C [24] BAI L Q, XUE N, ZHAO Y F, et al. Dual-mode emission of single-layered graphene quantum dots in confined nanospace: Anti-counterfeiting and sensor applications[J]. Nano Research, 2018, 11(4): 2034-2045. doi: 10.1007/s12274-017-1820-z [25] CAO Y, DONG H F, PU SH T, et al. Photoluminescent two-dimensional SiC quantum dots for cellular imaging and transport[J]. Nano Research, 2018, 11(8): 4074-4081. doi: 10.1007/s12274-018-1990-3 [26] LEI F C, LIU W, SUN Y F, et al. Metallic tin quantum sheets confined in graphene toward high-efficiency carbon dioxide electroreduction[J]. Nature Communications, 2016, 7: 12697. doi: 10.1038/ncomms12697 [27] XU H, ZHANG L, DING Z CH, et al. Edge-functionalized graphene quantum dots as a thickness-insensitive cathode interlayer for polymer solar cells[J]. Nano Research, 2018, 11(8): 4293-4301. doi: 10.1007/s12274-018-2015-y [28] DEB J, PAUL D, SARKAR U. Density functional theory investigation of nonlinear optical properties of T-graphene quantum dots[J]. The Journal of Physical Chemistry A, 2020, 124(7): 1312-1320. doi: 10.1021/acs.jpca.9b10241 [29] BRANDT O, LAGE H, PLOOG K. Large excitonic nonlinearity in InAs quantum sheets[J]. Applied Physics Letters, 1991, 59(5): 576-578. doi: 10.1063/1.105391 [30] BUTCHER P N, MCINNES J A. The energy dependence of the conductance and scattering wave functions of a 2D quantum dot[J]. Journal of Physics:Condensed Matter, 1995, 7(33): 6717-6726. doi: 10.1088/0953-8984/7/33/010 [31] 徐元清, 张勇. 首次实现二维量子片的普适和规模制备[J]. 物理,2019,48(8):522-525. doi: 10.7693/wl20190808XU Y Q, ZHANG Y. First demonstration of universal and scalable production of 2D QSs[J]. Physics, 2019, 48(8): 522-525. (in Chinese) doi: 10.7693/wl20190808 [32] ALLEN M J, TUNG V C, KANER R B. Honeycomb Carbon: a review of graphene[J]. Chemical Reviews, 2010, 110(1): 132-145. doi: 10.1021/cr900070d [33] ZHOU X J, GUO SH W, ZHONG P, et al. Large scale production of graphene quantum dots through the reaction of graphene oxide with sodium hypochlorite[J]. RSC Advances, 2016, 6(60): 54644-54648. doi: 10.1039/C6RA06012A [34] LI H L, TAY R Y, TSANG S H, et al. Controllable synthesis of highly luminescent boron nitride quantum dots[J]. Small, 2015, 11(48): 6491-6499. doi: 10.1002/smll.201501632 [35] DING X G, PENG F, ZHOU J, et al. Defect engineered bioactive transition metals dichalcogenides quantum dots[J]. Nature Communications, 2019, 10: 41. doi: 10.1038/s41467-018-07835-1 [36] SAMADI M, SARIKHANI N, ZIRAK M, et al. Group 6 transition metal dichalcogenide nanomaterials: synthesis, applications and future perspectives[J]. Nanoscale Horizons, 2018, 3(2): 90-204. doi: 10.1039/C7NH00137A [37] SPLENDIANI A, SUN L, ZHANG Y B, et al. Emerging photoluminescence in monolayer MoS2[J]. Nano Letters, 2010, 10(4): 1271-1275. doi: 10.1021/nl903868w [38] WANG Q H, KALANTAR-ZADEH K, KIS A, et al. Electronics and optoelectronics of two-dimensional transition metal dichalcogenides[J]. Nature Nanotechnology, 2012, 7(11): 699-712. doi: 10.1038/nnano.2012.193 [39] MIRÓ P, AUDIFFRED M, HEINE T. An atlas of two-dimensional materials[J]. Chemical Society Reviews, 2014, 43(18): 6537-6554. doi: 10.1039/C4CS00102H [40] CHURCHILL H O H, JARILLO-HERRERO P. Phosphorus joins the family[J]. Nature Nanotechnology, 2014, 9(5): 330-331. doi: 10.1038/nnano.2014.85 [41] LI L K, YU Y J, YE G J, et al. Black phosphorus field-effect transistors[J]. Nature Nanotechnology, 2014, 9(5): 372-377. doi: 10.1038/nnano.2014.35 [42] WANG Y, WANG X X, XU Y H, et al. Simultaneous synthesis of WO3−x quantum dots and bundle-like nanowires using a one-pot template-free solvothermal strategy and their versatile applications[J]. Small, 2017, 13(13): 1603689. [43] DING D D, GUO W, GUO CH SH, et al. MoO3−x quantum dots for photoacoustic imaging guided photothermal/photodynamic cancer treatment[J]. Nanoscale, 2017, 9(5): 2020-2029. doi: 10.1039/C6NR09046J [44] XUE Q, ZHANG H J, ZHU M SH, et al. Photoluminescent Ti3C2 MXene quantum dots for multicolor cellular imaging[J]. Advanced Materials, 2017, 29(15): 1604847. doi: 10.1002/adma.201604847 [45] LI R J, TANG L B, ZHAO Q, et al. In2S3 quantum dots: preparation, properties and optoelectronic application[J]. Nanoscale Research Letters, 2019, 14: 161. doi: 10.1186/s11671-019-2992-0 [46] HAMER M, TÓVÁRI E, ZHU M J, et al. Gate-defined quantum confinement in InSe-based van der Waals heterostructures[J]. Nano Letters, 2018, 18(6): 3950-3955. doi: 10.1021/acs.nanolett.8b01376 [47] CARTER S G, BRACKER A S, BRYANT G W, et al. Spin-mechanical coupling of an InAs quantum dot embedded in a mechanical resonator[J]. Physical Review Letters, 2018, 121(24): 246801. doi: 10.1103/PhysRevLett.121.246801 [48] RADISAVLJEVIC B, RADENOVIC A, BRIVIO J, et al. Single-layer MoS2 transistors[J]. Nature Nanotechnology, 2011, 6(3): 147-150. doi: 10.1038/nnano.2010.279 [49] BANDURIN D A, TYURNINA A V, YU G L, et al. High electron mobility, quantum Hall effect and anomalous optical response in atomically thin InSe[J]. Nature Nanotechnology, 2017, 12(3): 223-227. doi: 10.1038/nnano.2016.242 [50] MILLER T S, JORGE A B, SUTER T M, et al. Carbon nitrides: synthesis and characterization of a new class of functional materials[J]. Physical Chemistry Chemical Physics, 2017, 19(24): 15613-15638. doi: 10.1039/C7CP02711G [51] ALTAVILLA C, SARNO M, CIAMBELLI P. A novel wet chemistry approach for the synthesis of hybrid 2D free-floating single or multilayer nanosheets of MS2@oleylamine (M=Mo, W)[J]. Chemistry of Materials, 2011, 23(17): 3879-3885. doi: 10.1021/cm200837g [52] ARSLAN O, BELKOURA L, MATHUR S. Swift synthesis, functionalization and phase-transfer studies of ultrastable, visible light emitting oleate@ZnO quantum dots[J]. Journal of Materials Chemistry C, 2015, 3(45): 11965-11973. doi: 10.1039/C5TC03377B [53] LI X ZH, FANG Y Y, WANG J, et al. High-yield electrochemical production of large-sized and thinly layered NiPS3 flakes for overall water splitting[J]. Small, 2019, 15(30): 1902427. doi: 10.1002/smll.201902427 [54] GOPALAKRISHNAN D, DAMIEN D, LI B, et al. Electrochemical synthesis of luminescent MoS2 quantum dots[J]. Chemical Communications, 2015, 51(29): 6293-6296. doi: 10.1039/C4CC09826A [55] WANG W J, YU J C, SHEN ZH R, et al. g-C3N4 quantum dots: direct synthesis, upconversion properties and photocatalytic application[J]. Chemical Communications, 2014, 50(70): 10148-10150. doi: 10.1039/C4CC02543A [56] CHENG ZH ZH, SHIFA T A, WANG F M, et al. High-yield production of monolayer FePS3 quantum sheets via chemical exfoliation for efficient photocatalytic hydrogen evolution[J]. Advanced Materials, 2018, 30(26): 1707433. doi: 10.1002/adma.201707433 [57] WANG Y, LIU Y, ZHANG J F, et al. Cryo-mediated exfoliation and fracturing of layered materials into 2D quantum dots[J]. Science Advances, 2017, 3(12): e1701500. doi: 10.1126/sciadv.1701500 [58] ZHANG J F, ZHU T Y, WANG Y, et al. Self-assembly of 0D/2D homostructure for enhanced hydrogen evolution[J]. Materials Today, 2020, 36: 83-90. doi: 10.1016/j.mattod.2020.02.006 [59] HAO Y, SU W, HOU L X, et al. Monolayer single crystal two-dimensional quantum dots via ultrathin cutting and exfoliating[J]. Science China Materials, 2020, 63(6): 1046-1053. doi: 10.1007/s40843-019-1270-x [60] HAN CH CH, ZHANG Y, GAO P, et al. High-yield production of MoS2 and WS2 quantum sheets from their bulk materials[J]. Nano Letters, 2017, 17(12): 7767-7772. doi: 10.1021/acs.nanolett.7b03968 [61] SYNNATSCHKE K, CIESLIK P A, HARVEY A, et al. Length- and thickness-dependent optical response of liquid-exfoliated transition metal dichalcogenides[J]. Chemistry of Materials, 2019, 31(24): 10049-10062. doi: 10.1021/acs.chemmater.9b02905 [62] ZHANG X, LAI ZH CH, LIU ZH D, et al. A facile and universal top-down method for preparation of monodisperse transition-metal dichalcogenide nanodots[J]. Angewandte Chemie International Edition, 2015, 54(18): 5425-5428. doi: 10.1002/anie.201501071 [63] LIU Y, LIANG CH L, WU J J, et al. Reflux pretreatment-mediated sonication: a new universal route to obtain 2D quantum dots[J]. Materials Today, 2019, 22: 17-24. doi: 10.1016/j.mattod.2018.06.007 [64] XU Y Q, CHANG J Q, LIANG C, et al. Tailoring multi-walled carbon nanotubes into graphene quantum sheets[J]. ACS Applied Materials &Interfaces, 2020, 12(42): 47784-47791. [65] LIANG CH, SUI X Y, WANG A CH, et al. Controlled production of MoS2 full-scale nanosheets and their strong size effects[J]. Advanced Materials Interfaces, 2020, 7(24): 2001130. doi: 10.1002/admi.202001130 [66] AN T C, TANG J, ZHANG Y Y, et al. Photoelectrochemical conversion from graphitic C3N4 quantum dot decorated semiconductor nanowires[J]. ACS Applied Materials &Interfaces, 2016, 8(20): 12772-12779. [67] TANG L B, JI R B, LI X M, et al. Deep ultraviolet to near-infrared emission and photoresponse in layered N-doped graphene quantum dots[J]. ACS Nano, 2014, 8(6): 6312-6320. doi: 10.1021/nn501796r [68] KIM S, HWANG S W, KIM M K, et al. Anomalous behaviors of visible luminescence from graphene quantum dots: interplay between size and shape[J]. ACS Nano, 2012, 6(9): 8203-8208. doi: 10.1021/nn302878r [69] REN J, WEBER F, WEIGERT F, et al. Influence of surface chemistry on optical, chemical and electronic properties of blue luminescent carbon dots[J]. Nanoscale, 2019, 11(4): 2056-2064. doi: 10.1039/C8NR08595A [70] LI L L, JI J, FEI R, et al. A facile microwave avenue to electrochemiluminescent two-color graphene quantum dots[J]. Advanced Functional Materials, 2012, 22(14): 2971-2979. doi: 10.1002/adfm.201200166 [71] ZHOU M, LOU X W, XIE Y. Two-dimensional nanosheets for photoelectrochemical water splitting: possibilities and opportunities[J]. Nano Today, 2013, 8(6): 598-618. doi: 10.1016/j.nantod.2013.12.002 [72] LIU ZH K, LAU S P, YAN F. Functionalized graphene and other two-dimensional materials for photovoltaic devices: device design and processing[J]. Chemical Society Reviews, 2015, 44(15): 5638-5679. doi: 10.1039/C4CS00455H [73] MANIKANDAN A, CHEN Y Z, SHEN C C, et al. A critical review on two-dimensional quantum dots (2D QDs): from synthesis toward applications in energy and optoelectronics[J]. Progress in Quantum Electronics, 2019, 68: 100226. doi: 10.1016/j.pquantelec.2019.100226 [74] SK M A, ANANTHANARAYANAN A, HUANG L, et al. Revealing the tunable photoluminescence properties of graphene quantum dots[J]. Journal of Materials Chemistry C, 2014, 2(34): 6954-6960. doi: 10.1039/C4TC01191K [75] KWON W, KIM Y H, LEE C L, et al. Electroluminescence from graphene quantum dots prepared by amidative cutting of tattered graphite[J]. Nano Letters, 2014, 14(3): 1306-1311. doi: 10.1021/nl404281h [76] JIN S H, KIM D H, JUN G H, et al. Tuning the photoluminescence of graphene quantum dots through the charge transfer effect of functional groups[J]. ACS Nano, 2013, 7(2): 1239-1245. doi: 10.1021/nn304675g [77] ZHU X Q, XIANG J X, LI J, et al. Tunable photoluminescence of MoS2 quantum dots passivated by different functional groups[J]. Journal of Colloid and Interface Science, 2018, 511: 209-214. doi: 10.1016/j.jcis.2017.09.118 [78] BASKO D M, DUCHEMIN I, BLASE X. Optical properties of graphene quantum dots: the role of chiral symmetry[J]. 2D Materials, 2020, 7(2): 025041. doi: 10.1088/2053-1583/ab7688 [79] NIU X H, LI Y H, SHU H B, et al. Revealing the underlying absorption and emission mechanism of nitrogen doped graphene quantum dots[J]. Nanoscale, 2016, 8(46): 19376-19382. doi: 10.1039/C6NR06447G [80] YEH T F, TENG C Y, CHEN S J, et al. Nitrogen-doped graphene oxide quantum dots as photocatalysts for overall water-splitting under visible light illumination[J]. Advanced Materials, 2014, 26(20): 3297-3303. doi: 10.1002/adma.201305299 [81] TANG J M, SAKAMOTO M, OHTA H, et al. 1% defect enriches MoS2 quantum dot: catalysis and blue luminescence[J]. Nanoscale, 2020, 12(7): 4352-4358. doi: 10.1039/C9NR07612C [82] QU D, SUN Z CH, ZHENG M, et al. Three colors emission from S, N Co-doped graphene quantum dots for visible light H2 production and bioimaging[J]. Advanced Optical Materials, 2015, 3(3): 360-367. doi: 10.1002/adom.201400549 [83] ZHANG SH, JIA X F, WANG E K. Facile synthesis of optical pH-sensitive molybdenum disulfide quantum dots[J]. Nanoscale, 2016, 8(33): 15152-15157. doi: 10.1039/C6NR04726B [84] AUTERE A, JUSSILA H, DAI Y Y, et al. Nonlinear optics with 2D layered materials[J]. Advanced Materials, 2018, 30(24): 1705963. doi: 10.1002/adma.201705963 [85] LI J L, BAO H CH, HOU X L, et al. Graphene oxide nanoparticles as a nonbleaching optical probe for two-photon luminescence imaging and cell therapy[J]. Angewandte Chemie International Edition, 2012, 51(8): 1830-1834. doi: 10.1002/anie.201106102 [86] SUN J H, GU Y J, LEI D Y, et al. Mechanistic understanding of excitation-correlated nonlinear optical properties in MoS2 nanosheets and nanodots: the role of exciton resonance[J]. ACS Photonics, 2016, 3(12): 2434-2444. doi: 10.1021/acsphotonics.6b00682 [87] LIU Q, GUO B D, RAO Z Y, et al. Strong two-photon-induced fluorescence from photostable, biocompatible nitrogen-doped graphene quantum dots for cellular and deep-tissue imaging[J]. Nano Letters, 2013, 13(6): 2436-2441. doi: 10.1021/nl400368v [88] COX J D, SILVEIRO I, DE ABAJO F J G. Quantum effects in the nonlinear response of graphene plasmons[J]. ACS Nano, 2016, 10(2): 1995-2003. doi: 10.1021/acsnano.5b06110 [89] COX J D, DE ABAJO F J G. Plasmon-enhanced nonlinear wave mixing in nanostructured graphene[J]. ACS Photonics, 2015, 2(2): 306-312. doi: 10.1021/ph500424a [90] GRIGORENKO A N, POLINI M, NOVOSELOV K S. Graphene plasmonics[J]. Nature Photonics, 2012, 6(11): 749-758. doi: 10.1038/nphoton.2012.262 [91] LOW T, CHAVES A, CALDWELL J D, et al. Polaritons in layered two-dimensional materials[J]. Nature Materials, 2017, 16(2): 182-194. doi: 10.1038/nmat4792 [92] WANG Y W, LIU S, ZENG B W, et al. Ultraviolet saturable absorption and ultrafast carrier dynamics in ultrasmall black phosphorus quantum dots[J]. Nanoscale, 2017, 9(14): 4683-4690. doi: 10.1039/C6NR09235G [93] CHEN X, PONRAJ J S, FAN D Y, et al. An overview of the optical properties and applications of black phosphorus[J]. Nanoscale, 2020, 12(6): 3513-3534. doi: 10.1039/C9NR09122J [94] XU Y H, WANG ZH T, GUO ZH N, et al. Solvothermal synthesis and ultrafast photonics of black phosphorus quantum dots[J]. Advanced Optical Materials, 2016, 4(8): 1223-1229. doi: 10.1002/adom.201600214 [95] LU S B, MIAO L L, GUO Z N, et al. Broadband nonlinear optical response in multi-layer black phosphorus: an emerging infrared and mid-infrared optical material[J]. Optics Express, 2015, 23(9): 11183-11194. doi: 10.1364/OE.23.011183 [96] LU L, TANG X, CAO R, et al. Broadband nonlinear optical response in few-layer antimonene and antimonene quantum dots: a promising optical kerr media with enhanced stability[J]. Advanced Optical Materials, 2017, 5(17): 1700301. doi: 10.1002/adom.201700301 [97] WANG SH X, YU H H, ZHANG H J, et al. Broadband few-layer MoS2 saturable absorbers[J]. Advanced Materials, 2014, 26(21): 3538-3544. doi: 10.1002/adma.201306322 [98] ZHANG Y, WANG J J, BALLANTINE K E, et al. Hybrid plasmonic nanostructures with unconventional nonlinear optical properties[J]. Advanced Optical Materials, 2014, 2(4): 331-337. doi: 10.1002/adom.201300503 [99] WANG F, ROZHIN A G, SCARDACI V, et al. Wideband-tuneable, nanotube mode-locked, fibre laser[J]. Nature Nanotechnology, 2008, 3(12): 738-742. doi: 10.1038/nnano.2008.312 [100] BAO Q L, ZHANG H, NI ZH H, et al. Monolayer graphene as a saturable absorber in a mode-locked laser[J]. Nano Research, 2011, 4(3): 297-307. doi: 10.1007/s12274-010-0082-9 [101] SU L M, FAN X, YIN T, et al. Inorganic 2D luminescent materials: structure, luminescence modulation, and applications[J]. Advanced Optical Materials, 2020, 8(1): 1900978. doi: 10.1002/adom.201900978 [102] ZHENG J L, YANG ZH H, SI C, et al. Black phosphorus based all-optical-signal-processing: toward high performances and enhanced stability[J]. ACS Photonics, 2017, 4(6): 1466-1476. doi: 10.1021/acsphotonics.7b00231 [103] WANG X T, CUI Y, LI T, et al. Recent advances in the functional 2D photonic and optoelectronic devices[J]. Advanced Optical Materials, 2019, 7(3): 1801274. doi: 10.1002/adom.201801274 [104] LEE Y J, YEH T W, ZOU CH, et al. Graphene quantum dot vertical cavity surface-emitting lasers[J]. ACS Photonics, 2019, 6(11): 2894-2901. doi: 10.1021/acsphotonics.9b00976 [105] 孙俊杰, 陈飞, 何洋, 等. 新型过渡金属硫化物在超快激光中的应用[J]. 中国光学,2020,13(4):647-659. doi: 10.37188/CO.2019-0241SUN J J, CHEN F, HE Y, et al. Application of emerging transition metal dichalcogenides in ultrafast lasers[J]. Chinese Optics, 2020, 13(4): 647-659. (in Chinese) doi: 10.37188/CO.2019-0241 [106] YANG Y F, HU H W, WU M J, et al. Stretchable and broadband cavity-free lasers based on all 2D metamaterials[J]. Advanced Optical Materials, 2020, 8(7): 1901326. doi: 10.1002/adom.201901326 [107] GHIDIU M, LUKATSKAYA M R, ZHAO M Q, et al. Conductive two-dimensional titanium carbide ‘clay’ with high volumetric capacitance[J]. Nature, 2014, 516(7529): 78-81. doi: 10.1038/nature13970 [108] DING L, WEI Y Y, LI L B, et al. MXene molecular sieving membranes for highly efficient gas separation[J]. Nature Communications, 2018, 9: 155. doi: 10.1038/s41467-017-02529-6 [109] JIANG Q, WU CH SH, WANG ZH J, et al. MXene electrochemical microsupercapacitor integrated with triboelectric nanogenerator as a wearable self-charging power unit[J]. Nano Energy, 2018, 45: 266-272. doi: 10.1016/j.nanoen.2018.01.004 [110] HUANG D P, XIE Y, LU D ZH, et al. Demonstration of a white laser with V2C MXene-based quantum dots[J]. Advanced Materials, 2019, 31(24): 1901117. [111] ZHANG H, ROGERS J A. Recent advances in flexible inorganic light emitting diodes: from materials design to integrated optoelectronic platforms[J]. Advanced Optical Materials, 2019, 7(2): 1800936. doi: 10.1002/adom.201800936 [112] LU G ZH, WU M J, LIN T N, et al. Electrically pumped white-light-emitting diodes based on histidine-doped MoS2 quantum dots[J]. Small, 2019, 15(30): 1901908. doi: 10.1002/smll.201901908