Direct Z-Scheme g-C 3 N 4 /FeWO 4 Nanocomposite for Enhanced and Selective Photocatalytic CO 2 Reduction under Visible Light.

Photocatalytic reduction of CO2 to renewable solar fuels is considered to be the promising strategy to simultaneously solve both the global warming and energy crises. However, development of superior photocatalytic system with high product selectivity for CO2 reduction under solar light is the prime requisite. Herein, a series of nature-inspired Z-scheme g C3N4/FeWO4 composites are prepared for higher performance and selective CO2 reduction to CO as solar fuel under solar light. The novel direct Z-scheme coupling of the visible light active FeWO4 nanoparticles with C3N4 nanosheets is seen to exhibit excellent performance for CO production with a rate of 6µmol/g/hr at ambient temperature, almost 6 times higher compared to pristine C3N4 and 15 times higher than pristine FeWO4.More importantly, selectivity for CO is 100% over other carbon products from CO2 reduction and more than 90% over H2 product from water splitting. Our results clearly demonstrate that the staggered band structure between FeWO4 and C3N4 reflecting nature-inspired Z-scheme system not only favors superior spatial separation of electron-hole pair in g-C3N4/FeWO4, but also shows good reusability. The present work provides unprecedented insights for constructing the direct Z-scheme by mimicking nature for high performance and selective photocatalytic CO2 reduction into solar fuels under solar light.