Intensification of heterogeneous photocatalytic reactions using wireless light emitters: the case study of nitrobenzene reduction†

Delocalized internal irradiation is a promising technique to intensify and scale up photochemical processes, as it prevents the otherwise unavoidable concentration of light energy. In particular, wireless light emitters (WLEs) powered by resonant inductive coupling showed promise in previous studies. However, the achieved photon flux was still relatively low. Herein, we show that through systematic optimization, the WLE technique can reach extremely high photon flux densities and energy efficiency, surpassing conventional photochemical reaction systems. Moreover, the intensification potential is demonstrated on the basis of a case study: the photocatalytic reduction of nitrobenzene in isopropanol using a TiO₂ photocatalyst. The results also reveal a significant advantage of the WLE system. Due to the decentralized light emitters, the local accumulation of photon energy is minimized, preventing efficiency losses due to kinetic limitations at high light intensity.