Cellulose template designed porous ZnO based catalysts with different valence copper for solar photocatalytic CO2 conversion

Abstract

Designing a green method to enhance the utilization of photocatalysts on solar energy was of great significance to alleviate energy problems. The porous ZnO-based catalysts with different valence copper (CuO−ZnOCel-T and Cu−ZnOCel-T) were successfully obtained by using cellulose fibers as templates, which possessed three-dimensional structures and excellent photocatalytic activities. The dispersibility of CuO−ZnOCel-T nanoparticle was influenced by surface groups of cellulose template, the more active sites of composite catalyst were exposed than CuO−ZnO catalysts with carbon fiber as the template and CuO−ZnO powders without any template. Moreover, to explore the effects of different valence states of Cu on the photocatalytic activity of ZnO nanoparticles, wheat straw was used to reduce CuO−ZnOCel-T to Cu−ZnOCel-T by using pyrolysis reduction treatment of wheat straw. The CO production rate of Cu−ZnOCel-T (30.17 µmol*g−1h−1) was significantly higher than CuO−ZnOCel-T (8.61 µmol*g−1h−1) based on the same catalyst morphologies, indicating that the surface plasmon resonance (SPR) effect of Cu was more favorable for improving catalytic activities of ZnO than the structure effect of CuO−ZnOCel-T heterojunction. This work proposed an exciting idea for using biomass materials to tailor the photocatalytic performance of catalysts and reduce copper ions in a cleaner method.