Boosted photocatalytic CO2 reduction by induced electromotive force in rotating magnetic field

Charge separation plays a crucial role in semiconductor-based photocatalytic CO2 conversion. Herein, we developed a photo-magnetic coupling reactor to manipulate a unique induced electric field, which can control carrier behavior at the minuscule and boost the photocatalytic reduction of CO2. A monolithic photocatalyst consisting of a copper foam substrate and nanosized ZnO/NiO/Au heterostructures was designed to couple the rotating magnetic field (RMF) in the reactor. Specifically, induced electric field is generated by copper foam cutting the magnetic induction line, which can increase the charge carrier density by preventing their recombination. Moreover, NiO and Au synergistically magnify the charge separation as the active sites for the oxidation and reduction reaction, respectively. The utilization rate of photogenerated electrons increases by 5.24 times after coupling RMF, with the yields of CO and CH4 improved by 5.50 times and 5.18 times. This strategy of integrating the distinct RMF into the reaction provides new insights for improving photocatalytic CO2 conversion.