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 CO ₂ to renewable solar fuels is considered to be a promising strategy to simultaneously solve both global warming and energy crises. However, development of a superior photocatalytic system with high product selectivity for CO ₂ reduction under solar light is the prime requisite. Herein, a series of nature-inspired Z-scheme g C ₃ N ₄ /FeWO ₄ composites are prepared for higher performance and selective CO ₂ reduction to CO as solar fuel under solar light. The novel direct Z-scheme coupling of the visible light-active FeWO ₄ nanoparticles with C ₃ N ₄ nanosheets is seen to exhibit excellent performance for CO production with a rate of 6 μmol/g/h at an ambient temperature, almost 6 times higher compared to pristine C ₃ N ₄ and 15 times higher than pristine FeWO ₄ . More importantly, selectivity for CO is 100% over other carbon products from CO ₂ reduction and more than 90% over H ₂ products from water splitting. Our results clearly demonstrate that the staggered band structure between FeWO ₄ and C ₃ N ₄ reflecting the nature-inspired Z-scheme system not only favors superior spatial separation of the electron-hole pair in g-C ₃ N ₄ /FeWO ₄ but also shows good reusability. The present work provides unprecedented insights for constructing the direct Z-scheme by mimicking the nature for high performance and selective photocatalytic CO ₂ reduction into solar fuels under solar light.