Heterogeneous photocatalytic hydrogen production (photocatalytic hydrogen evolution reaction, PCHER) provides a promising pathway to directly harvest and convert clean intermittent solar energy into storable chemical fuel. PCHER endows lower fabrication and setup cost than the photoelectrochemical (PEC) or photovoltaic–electrocatalytic (PV–EC) devices. Yet, the average solar-to-hydrogen (STH) efficiency of current research and development remains far below the targeted 5%. Focusing on the bottleneck of the PCHER technology, i.e. energy conversion efficiency, this chapter provides an overview of the historical development and principle of PCHER in semiconducting catalysts. Subsequently, it introduces current practical approaches to improve STH for one-step and two-step charge transfer processes. The impact of operational parameters and photocatalytic reactors on the STH is later discussed. We summarize the chapter with perspectives and outlook on future PCHER research and development.