Carbon nano-layer coated TiO2 nanoparticles for efficient photocatalytic CO2 reduction into CH4 and CO

Abstract

Solar-driven photocatalytic reduction of CO2 into value-added fuel is an exciting concept that can address serious global challenges such as greenhouse effect and energy crisis. However, the low sunlight utilization by the photocatalysts and their high production costs have greatly hindered their mass adoption. Herein, we proposed a facile and efficient approach to prepare the carbon nano-layer coated TiO2 as an efficient photocatalyst for the photocatalytic reduction of CO2 into CH4 and CO. By pyrolyzing linear low-density polyethylene, a carbon nano-layer was formed on the surface of TiO2. The obtained carbon nano-layer coated TiO2 was able to exhibit superior photocatalytic CO2 reduction activity as compared to its unmodified counterpart, whereby, a CH4 production rate of ~2.30 μmol · g−1 h−1 was achieved (prepared at a dwelling temperature of 600 °C). Meanwhile, a CO production rate of ~16.76 μmol · g−1 h−1 was recorded for the materials prepared at a dwelling temperature of 500 °C. The enhanced CH4 and CO production can be attributed to the elevated absorbance in the visible-light region, decreased band gap and effective restriction of photogenerated electron-hole pair recombination. Thus, based on the results, carbon nano-layer coated TiO2 can be a promising alternative for the photocatalytic reduction of CO2 into valuable fuel for large-scale application.