Recent progress in red phosphorus-based photocatalysts for photocatalytic water remediation and hydrogen production

Elemental red phosphorus (RP) photocatalyst has drawn considerable attention to solve the problem of water and energy scarcity because of its availability in abundance, wide response in the visible region, low cost, non-toxicity, and tunable band gap (1.5 eV-2.4 eV). Additionally, it possesses some interesting structural and photocatalytic properties which make it a potential photocatalyst. However, it possesses lower charge carrier mobility because of the presence of charge trapping sites on its surface which restricted its photocatalytic activity in comparison to other traditional photocatalysts. Therefore, various strategies such as preparation of crystalline and nanostructured RP, cocatalyst loading, and construction of heterojunction with RP have been explored to enhance the photocatalytic performance of RP. Over the past few years, significant efforts have been done to develop various RP-based photocatalysts using these strategies. These materials have broad applications in photocatalytic wastewater treatment and water splitting. This review seeks to provide an overview of the progress made so far in photocatalytic water treatment and hydrogen generation applications using RP-based photocatalysts. It starts off with a discussion of the fundamentals and mechanisms of photocatalysis technique, followed by a discussion on the structural, photocatalytic properties and its applications for wastewater treatment and hydrogen production. Finally, it concludes with proposed challenges and perspectives for the future development of advanced RP-based photocatalysts.