To handle global problems of energy and environmental pollution, efforts have been made to harvest energy from sunlight. Photoelectrochemcal water splitting is an efficient way to achieve sustainable solar-fuel production. However, to make this method competitive to traditional methods, low-cost, abundant and high-performance semiconductor materials are required. Among which, Cu2O is a promising candidate. Conformal atomic layer deposited layers are applied on the photocathode to improve performance and stability. Electrodeposited catalyst composing earth-abundant elements are used to decrease kinetic barrier. A great enhancement on overall performance is achieved.