Insight into the photoelectric characteristics and photocatalytic water splitting performances of van der Waals heterostructures Cs 2 PbI 4 /MX 2 (M = Mo, W; X = Se, S)

heterostructure is 1.27 V, the low overpotential for the OER is 0.31 V, and the high power conversion efficiency indicates that it may have potential applications in both solar cells and photocatalytic water splitting.