▎ 摘　　要

Development of atomic layers and their heterostructures opened new avenues in developing novel photocatalysts for enhanced light matter interaction. Graphene hexagonal boron nitride (G/hBN) van der Waals structures were recently predicted for interfacial exciton generation upon visible light excitation, and also, the authors have shown their van der Waals stacking-induced electrocatalytic activity. Here, an enhanced photo-electrocatalytic hydrogen evolution reaction (HER) is demonstrated upon white light illumination on samples where graphene and hBN are stacked via van der Waals interaction. The individual layers of graphene and hBN-modified electrodes have no light induced effects along with a "poor" electrocatalytic HER activity. The origin of such light induced activity is probed via density-functional-theory-based calculations. The catalytic activity of such heterostructures is found to be further enhanced by nanostructuring, where the coupling between individual defective graphene layers is ensured via direct carbon carbon coupling through the Suzuki reaction. With band-engineering-induced inherent activity enhancement and nanostructuring-enabled enhanced active sites, we were able to develop a G/hBN structure that has an exceptional photo-electrocatalytic activity.