Photocatalyst Design for Photoelectrochemical Energy Conversion

To achieve a sustainable development especially in energy harvesting, storage and utilization, tremendous efforts have been made toward renewable green energy carriers, such as hydrogen and ammonia, having attracted substantial attentions to the production of H2 and NH3 via a photoelectrochemical (PEC) procedure, which is very promising to convert solar energy into fuel. In this thesis, the foundation of PEC process especially for water splitting and nitrogen reduction are firstly summarized, including basic mechanisms, performance assessment, impacting factors, existing challenges, and corresponding strategies, etc. Besides, the earth-abundant inexpensive cuprous oxide integrated with a highly polymerized red carbon nitride as photocathodes for PEC water splitting is prepared and systematically investigated. A p-n heterojunction is constructed between cuprous oxide and red carbon nitride especially with a distinctive weak electron exchange via the Cu+ in cuprous oxide and C=N-C group in red carbon nitride, leading to lower resistance of charge transfer and faster mass transfer rate and further an improved PEC performance.