TiO2 Facet-dependent reconstruction and photocatalysis of CuOx/TiO2 photocatalysts in CO2 photoreduction

A series of CuOx/TiO2 photocatalysts with different TiO2 nanocrystals as the supports were prepared to explore the effect of CuOx-TiO2 interaction on the reconstruction and photocatalysis in CO2 photoreduction with water as the reducing agent. The CuOx-TiO2 interaction was observed to be strongest in CuOx/TiO2-{001} photocatalysts. Under Xe light irradiation, supported CuO species on TiO2-{001} is photo-reduced to stable supported Cu2O species beneficial for photocatalytic CO2 reduction to CH4, while supported CuOx species on TiO2-{100} and TiO2-{101} is photo-reduced to supported Cu-0 species unfavorable for photocatalytic CO2 reduction to CH4. The photo-induced reduction of supported CuOx to Cu-0 becomes more severe under Hg light irradiation. In situ diffuse reflectance infrared spectroscopy (DRIFTS) results demonstrate that photocatalytic CO2 reduction to CH4 occurs via the bicarbonate and carboxyl intermediates over all CuOx/TiO2 photocatalysts and via the additional CO2- and formate intermediates over CuOx/TiO2-{100} and CuOx/TiO2-{101} photocatalysts. These results deepen the fundamental understanding of Cu-based photocatalysts for photocatalytic CO2 reduction and exemplify the facet effect of TiO2 nanocrystals in TiO2-related photocatalysis.

一系列具有不同TIO2纳米晶体的CUOX/TIO2光催化剂作为支持，以探索Cuox-Tio2相互作用对CO2用水作为还原剂的CO2光降低的重建和光催化的影响。观察到Cuox-TiO2相互作用在Cuox/TiO2- {001}光催化剂中最强。在XE光照射下，将Tio2- {001}的受支持的CuO物种归还为稳定的受支持的Cu2O物种，对将光催化CO2还原为CH4有益，而在Tio2- {100}上支撑的Cuox物种则支持Cu-0的Cu-0 co cu-cu-0 co co co co co co co co co co co co co co co co co co co co coportial cu co的co cu co co co co coporation for cu co co coptordsptical copptical codptptpt的cu co coppotec co的。在HG的光照射下，照片引起的支持的Cuox对Cu-0的减少变得更加严重。原位弥漫性反射红外光谱（漂移）结果表明，光催化CO2还原为CH4，通过碳酸氢盐和羧基中间体发生在所有CUOX/TIO2光催化剂上，以及其他CO2-和其他co2-和formate中间体的cuox/tio2-/tio2-} 1001和CUOX {101和CUOX/TIOS/TIOS/TIOS/TIOS/TIO.2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-11/TOMATS和CUOX。这些结果加深了对基于Cu的光催化剂的基本理解，以减少光催化CO2的减少，并体现了TIO2纳米晶体在TIO2相关光催化中的占相位效应。