半导体量子点和碳点基零维/二维异质结光催化剂构筑及应用

Construction and Application of Semiconductor Quantum Dots and Carbon Dots Based 0D/2D Heterojunction Photocatalysts

半导体量子点因其具有精准的尺寸调控、独特的光电特性、丰富的表面活性位点等优势,在光催化剂设计和机理研究中获得了广泛关注。与传统半导体量子点主要作为光吸收单元不同,新兴的碳点更是在增加光吸收、促进电荷分离和增加表面反应位点等光催化不同环节均展现出优异的应用潜力。然而,量子点光催化剂由于小尺寸带来电荷复合严重、易团聚、稳定性差等问题而限制了其光催化性能。解决这些问题的主要途径之一是将零维(0D)量子点负载到超薄的二维(2D)纳米片上,形成0D/2D纳米复合材料,使量子点更加分散和稳定,且2D纳米材料促进的加速电荷转移能够抑制光生电荷的复合,从而可以有效地改善量子点基光催化剂的催化活性和稳定性。本文系统阐述了半导体量子点和碳点基0D/2D异质结光催化剂的构筑及应用,着重讨论了不同类型0D/2D异质结的光催化作用机理及面临的挑战,最后对其未来发展进行了分析和展望。

Semiconductor quantum dots(QDs)have attracted much attention in the design and mechanism of photocatalysts due to their precise size control,unique photoelectric properties and abundant surface active sites.Unlike traditional semiconductor QDs that are mainly used as light absorption units,the emerging carbon dots show excellent application potential in different aspects of photocatalysis,such as enhancing light absorption,promoting charge separation,and increasing surface reaction sites.However,the small size of QDs photocatalysts also leads to serious charge recombination,easy agglomeration and poor stability,which severely limits their photocatalytic performance.One of the main pathways to solve these problems is to load zero dimensional(0D)QDs on ultra-thin two-dimensional(2D)nanosheets to form 0D/2D nanocomposites,which can make the QDs better dispersed and more stable.The accelerated charge transfer promoted by 2D nanosheets can inhibit the recombination of photogenerated charges carriers,which can subsequently improve the activity and stability of QDs-based photocatalysts.In this review,the construction and application of semiconductor QDs and carbon dots based 0D/2D heterojunction photocatalysts are systematically introduced,with special attention to the discussion of the mechanism and challenges of different types of 0D/2D heterojunction photocatalysts.Finally,future development is analyzed and prospected for the 0D/2D heterojunction photocatalysts.