Recent advances in carbon-based material/semiconductor composite photoelectrocatalysts: Synthesis, improvement strategy, and organic pollutant removal

Photoelectrocatalysis (PEC) technology has attracted broad interest due to its great application potential in pollutant removal and energy production. However, the high recombination of photogenerated electron-hole pairs, low utilization efficiency of solar energy, and limited reaction area are still the main obstacles that limit the practical applications of PEC. Carbon-based materials with unique and excellent properties are widely coupled with semiconductors to prepare composite photoelectrocatalysts to address the above problems. Carbon-based materials can serve as supporting materials, conductive substrates, electron transfer media, photosensitizers, and stabilizers to greatly improve the photoelectrocatalytic performance of semiconductors. Meanwhile, carbon-based materials can exert semiconductor properties to generate electron-hole pairs or construct heterojunctions with semiconductors to efficiently promote charge separation. In this review, a comprehensive summary is given to introduce synthetic methods and improvement strategies of carbon-based material/semiconductor composite photoelectrocatalysts, as well as their latest applications in the removal of organic pollutants. Especially, the roles of carbon-based materials in the PEC process are highlighted. Finally, current challenges and prospects are put forward. We do hope that this article can outline the recent advances and provide new insights for the future development of carbon-based semiconductor photoelectrocatalysts applied in water treatment.