Heterojunction: important strategy for constructing composite photocatalysts
基本信息来源于合作网站,原文需代理用户跳转至来源网站获取
摘要:
As an ideal solution to energy and environment issues,conversion of sunlight into solar fuels by photocatalytic water splitting and greenhouse gas (CO2) reduction has attracted keen research interest of multi-field scientists.In the past four decades,a large number of semiconductor photocatalysts have been developed for these uses.However,to date,none of the reported photocatalysts meet really the requirements of large-scale industrialization in solar conversion efficiency.Thus,development of high efficient photocatalysts has been a research focus and an open challenge.
In principle,there are three basic factors for consideration in the design and preparation of semiconductor photocatalysts:(1) suitable bandgap energy for wide sunlight response,(2) ability for quickly separating and transferring photogenerated charges,and (3) the well-matched valence and conduction band positions to redox potentials of the substrates.Various single-component or single-phase semiconductor materials,such as the oxides,sulfides,nitrides,etc.,have been showed to difficultly satisfy the three requirements simultaneously as photocatalysts,due to their less flexibility in regulating gap energy,separation and migration rates of photogenerated charges,and the valence and conduction band positions by doping [1].Therefore,hybrid or composite semiconductor photocatalysts will become an inexorable trend of the development of photocatalysts.