FeOCl and graphitic carbon nitride heterostructure bifunctional catalyst for electrochemical water splitting

Abstract Two-dimensional materials offer considerable potential in electrocatalytic water splitting however, their inherent activity can be further enhanced by improving electronic properties of these materials with interface engineering that can play an important role in fabricating heterostructures. Herein, we fabricated a heterostructure catalyst comprising FeOCl integrated with g-C 3 N 4 via a low-temperature thermal annealing method. The as-synthesized electrocatalyst was investigated via UV–visible, FTIR, XRD, SEM, EDS and XPS analysis. Electrochemical analysis revealed that the as-prepared catalyst efficiently catalyzes both hydrogen and oxygen evolution reactions represented as HER and OER during water splitting. FeOCl/g-C 3 N 4 exhibited the best HER performance, achieving an overpotential of 235 mV at a current density of 10 mA cm −2 , accompanied by a Tafel slope of 86.26 mV dec −1 . The synthesized catalyst also demonstrated efficient electrocatalytic performance for OER. Chronoamperometric test revealed the stable nature of the synthesized electrocatalyst by retaining electrocatalytic activity for up to 24 h on glassy carbon electrode (GCE). Additionally, the reduced charge transfer resistance and increased active surface area contributed to enhanced interfacial kinetics at the heterostructure, rendering it as an efficient water-splitting catalyst. This is the first report on the electrocatalytic role of FeOCl/g-C 3 N 4 as a bifunctional water splitting electrocatalyst with appealing figures of merit. This advancement in high performance water splitting catalysis can drive clean energy technologies for progressing research towards no or lower carbon emissions.