A direct Z-scheme α-Fe2O3/LaTiO2N visible-light photocatalyst for enhanced CO2 reduction activity

The overall conversion of carbon dioxide (CO2) with pure water to hydrocarbons is one of the most challenging reactions in the field of photocatalysis. Herein, LaTiO2N coupled with alpha-Fe2O3 is reported to achieve the overall conversion of gas phase CO2 without sacrificial agents under visible light irradiation. The optimal alpha-Fe2O3/LaTiO2N sample exhibits the yields of CO and CH4 up to 29.0 and 38.0 mu mol g(-1) under illumination for 3 h, with a total utilized photoelectron number (UPN) of 362.0 mu mol g(-1). The superior photocatalytic performance can be due to the efficient coupling of photocatalytic CO2 reduction and H2O oxidation over LaTiO2N and alpha-Fe2O3, respectively. Strong evidence of Z-scheme charge transfer pathway is illustrated by XPS, photoelectrochemical characterization, TRPL, Kelvin probe technique (KP), EPR and photoinduced redox probe reactions. This work is expected to provide new insights into promoting the photocatalytic performance of LaTiO2N by modulating the charge carrier dynamics.

Automated summary

The overall conversion of carbon dioxide to hydrocarbons using pure water is a challenging reaction in photocatalysis. LaTiO2N coupled with alpha-Fe2O3 achieved this conversion without sacrificial agents under visible light irradiation, showing high yields of CO and CH4. The efficient coupling of CO2 reduction and H2O oxidation over LaTiO2N and alpha-Fe2O3, respectively, contributed to the superior photocatalytic performance.