Since the report of the Honda–Fujishima effect, heterogeneous photocatalysis has attracted much attention around the world because of its potential energy and environmental applications. Although great progresses have been made in recent years, most were focused on preparing highly-active photocatalysts and investigating visible light utilization. In fact, we are still unclear on the thermodynamic and kinetic nature of photocatalysis to date, which sometimes leads to misunderstandings for experimental results. It is timely to give a review and discussion on the thermodynamics and kinetics of photocatalysis, so as to direct future researches. However, there is an absence of a detailed review on this topic until now. In this article, we tried to review and discuss the thermodynamics and kinetics of photocatalysis. We explained the thermodynamic driving force of photocatalysis, and distinguished the functions of light and heat in photocatalysis. The Langmuir–Hinshelwood kinetic model, the ˙OH oxidation mechanism, and the direct–indirect (D–I) kinetic model were reviewed and compared. Some applications of the D–I model to study photocatalytic kinetics were also discussed. The electron transport mode and its importance in photocatalysis were investigated. Finally, the intrinsic relation between the kinetics and the thermodynamics of photocatalytic reactions was discussed.

CuCoO₂ crystals were prepared at 100 °C through a hydrothermal method and used for the oxygen evolution reaction in alkaline solution.

The optimal hydrothermal synthesis of a Co@CoTe₂-240 electrode needs an overpotential of 286 mV to achieve a current density of 10 mA cm⁻² and is able to sustain galvanostatic OER electrolysis for 16 hours with little degradation of less than 20 mV.

Fe-doped TiO₂was prepared by hydrothermal treating Ti peroxide sol with different amount of iron nitrate. Fe ions can enter TiO₂lattice by substituting Ti⁴⁺ions, which significantly affect the crystallinity and morphology of TiO₂nanoparticles. Fe doping also influences the UV-Vis absorption and photoluminescence of TiO₂, due to the change of electronic structure. It is shown that Fe ions are more easily doped on TiO₂surface than in bulk. The theoretical computation based on the density functional theory (DFT) shows that the Fe ions in TiO₂bulk are localized and mainly act as the recombination centers of photoinduced electrons and holes. Some results support that the Fe³⁺ions on surface can form intermediate interfacial transfer pathway for electrons and holes, which is beneficial for increasing the photocatalytic activity of TiO₂. The photocatalytic activity first increases and then decreases as the Fe concentration increases, which is coaffected by the bulk-doped and surface-doped Fe ions.