Z-type heterojunction of Cu2O-modified layered BiOI composites with superior photocatalytic performance for CO2 reduction

Abstract

For solar energy conversion and energy mitigation relief, the development of an efficient and stable photocatalyst is critical. A Z-type Cu2O-modified BiOI microspheres were synthesized by chemical deposition. A series of xCu2O/BiOI (x = 0.6, 0.8, 1.0) has improved CO2 photoreduction performance under simulated sunshine irradiation, and the best yields of CH3OH and C2H5OH were 609.05 and 273.96 μmol/gcat, respectively, which were 2.65 and 2.88 times larger than that of pure BiOI. The material exhibits strong photocatalytic performance, which is mainly owing to a greater interaction between Cu2O and BiOI, which promotes the separation and migration of photogenerated carriers as well as the use of sunlight. The specific surface areas of pure BiOI and 10% Cu2O/BiOI were 12.05 and 22.85 m2/g, respectively, as shown in the N2 adsorption-desorption characterization, indicating that the introduction of Cu2O increased the specific surface area of BiOI and provided more active sites. Various characterizations were carried out to evaluate the morphological structure of the Z-type composite of Cu2O/BiOI composite catalyst and to investigate a possible mechanism of CO2 reduction. The CO2 reduction performance of the composite catalyst did not decrease significantly through five cycles of testing, indicating that the material has good stability and redox performance. This research suggests that photocatalysts could be useful in solar energy conversion and energy crisis mitigation.