Photoexcited singlet enhanced oxygen reduction reaction with high selectivity on the photosensitizer/layered double hydroxides nanocomposite

Oxygen reduction reaction(ORR)plays a pivotal role in advanced electrochemical energy conversion devices.However,the ORR conversion efficiency is extremely limited.The major obstacles originate from the adsorption and activation of O_(2)on the electrode surface.A novel nanocomposite catalyst,photosensitizers(PS)meso-tetraphenylporphyrin iron(III)chloride(FePcCl)/NiCoFe-layered double hydroxides(NiCoFe-LDHs)is designed in this study.Herein,owing to excellent oxygen molecules activation ability and remarkable illumination absorption feature,FePcCl/NiCoFe-LDHs is employed to uncover the relationship between the intrinsic ORR activity and PS behaviour.Interestingly,the reaction mechanism of singlet 1O_(2)is proposed owing to the combination of electrochemical ORR catalysed via LDHs and PS.The boosted cathodic ORR properties exhibit singlet 1O_(2)dependent response arising from the synergistic effect to selectively produce active intermediates in alkaline medium.This work imparts the promising new mechanism about the high 4-electron ORR selectivity via material design,which will guide the development of photo-assisted energy conversion devices.