Flower-like iron sulfide/cobaltous sulfide heterostructure as advanced electrocatalyst for oxygen evolution reaction

Developing efficient non-noble metal catalysts is crucial for promoting the electrochemical production of oxygen from water. In this work, a flower-like FeS/Co3S4 heterostructure composite on carbon cloth can be fabricated with a simple sulfurization method. As-prepared FeS/Co3S4 composite shows excellent oxygen evolution reaction (OER) performance with a low overpotential of 252 mV at 10 mA cm−2 and a small Tafel slope of 58 mV dec−1, better than the FeS and Co3S4 electrodes. In addition, the FeS/Co3S4 composite displays outstanding structural stability with any decay over long-time testing. The improved OER catalytic performance of FeS/Co3S4 composite is ascribed to the increased specific surface area and formation of FeS/Co3S4 heterojunction. Besides, theoretical calculation results also show that the FeS/Co3S4 heterojunction possesses a stronger adsorption ability to ∗OH, which is more favorable to the OER than the single FeS and Co3S4 counterpart. Our work has paved a new way of exploring high-efficient catalysts for OER.