Photocatalytic fuel cells: Fundamentals and applications

The global concerns surrounding the energy crisis and environmental pollution have recently escalated. Photocatalytic fuel cells (PFCs) emerge as promising energy conversion devices that harness solar energy. These PFCs utilize cost-effective semiconductor electrodes to spontaneously convert the chemical energy of renewable fuels or pollutants, alongside oxidants, into electricity. What sets PFCs apart is their amalgamation of photoelectrochemical and fuel cell concepts, offering dual benefits to address both environmental and energy challenges. The engineering concept behind PFCs is elegantly simple, relying solely on light as the driving force. Consequently, constructing affordable PFC devices becomes feasible, providing effective solutions for local environmental pollution and low-power energy consumption devices. This work delves into essential definitions, working principles, and the theoretical underpinnings of PFCs. It also offers a practical tutorial on constructing these devices and conducting half-cell reaction tests to evaluate PFC performance. Furthermore, some recent application cases will be thoroughly discussed, with a primary focus on critically analyzing strategies to enhance the efficiency and stability of PFCs.