BiOCl/g-C3N4异质结催化剂可见光催化还原CO2

以KCl、Bi（NO₃）₃和类石墨氮化碳（g-C₃N₄）为前体，采用水热法成功制备了BiOCl/g-C₃N₄异质结光催化剂，并进行可见光催化还原CO₂，考察了催化剂的活性及稳定性，同时研究BiOCl：g-C₃N₄（摩尔比）、催化剂用量和光照强度对光催化还原CO₂的影响。结果表明，在水蒸气的存在下，BiOCl/g-C₃N₄较纯BiOCl和g-C₃N₄具有更高的光催化还原CO₂活性，在催化剂用量为0.1 g，光照强度为2.413×10^-6 einstein·min^-1·cm^-2，BiOCl：g-C₃N₄摩尔比为1：1的异质结催化剂显示了最高的光催化还原CO₂活性，且可见光催化剂在5次套用实验后其活性基本不变。基于X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X射线光电子能谱（XPS）、比表面积测试（BET）和紫外-可见（UV-vis）吸收光谱表征，可以推断BiOCl和g-C₃N₄之间形成的p-n结能有效分离光生电子和空穴，是增强光催化剂活性的主要原因。

BiOCl/g-C3N4 heterojunction catalyst for efficient photocatalytic reduction of CO2 under visible light

BiOCl/g-C₃N₄ heterojunction catalyst was synthesized by a hydrothermal method using KCl, Bi(NO₃)₃ and g-C₃N₄ as precursors, over which the photocatalytic reduction of CO₂ under visible light irradiation was conducted. The catalytic activity and the stability during CO₂ photoreduction was studied. Moreover, effects of molar ratio of BiOCl to g-C₃N₄, usage amount of catalyst and illumination intensity on the photocatalytic reduction of CO₂ was investigated. It suggests that the BiOCl/g-C₃N₄ heterojunction catalysts showed much enhanced photocatalytic activities for the reduction of gaseous CO₂ with water vapor in comparison with BiOCl and g-C₃N₄. The BiOCl/g-C₃N₄ catalyst with molar ratio of 1:1 exhibited the highest photocatalytic activity for CO₂ reduction under the optimal conditions of 0.1 g catalyst and 2.413×10^-6 einstein·min^-1·cm^-2 of illumination intensity. Moreover, the catalyst maintained stable performance even after five cycles of test. Techniques of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller analyses and UV-vis absorption spectroscopy were conducted on the catalyst, and it is speculated that the effective separation of photogenerated electrons and holes due to the formation of p-n heterojunctions between BiOCl and g-C₃N₄ accounted for the improved photocatalytic activities of BiOCl/g-C₃N₄.