Recent advances in solar‐driven CO2 reduction over g‐C3N4‐based photocatalysts

Abstract

Abstract The persistent increase of CO2 levels in the atmosphere, already exceeding 400 ppm, urges the exploration of CO2 emission reduction and recycling technologies. Ideally, photocatalytic conversion of CO2 into valuable hydrocarbons realizes solar‐to‐chemical energy conversion, which is a desirable “kill two birds with one stone” strategy; namely, CO2 photoreduction can simultaneously tackle energy shortage and keep global carbon balance. Graphitic carbon nitride (g‐C3N4) working on CO2 reduction reaction deserves a highlight not only for the metal‐free feature that endows it with low cost, tunable electronic structure, and easy fabrication properties but also because of its strong reduction ability. The present review concisely summarizes the latest advances of g‐C3N4‐based photocatalysts toward CO2 reduction. It starts with the discussion of thermodynamics and dynamics aspects of the CO2 reduction process. Then the modification strategies to promote g‐C3N4‐based photocatalysts in CO2 photoreduction have been discussed in detail, including surface functionalization, molecule structure engineering, crystallization, morphology engineering, loading cocatalyst, and constructing heterojunction. Meanwhile, the intrinsic factors affecting CO2 reduction activity and selectivity are analyzed and summarized. In the end, the challenges and prospects for the future development of highly g‐C3N4‐based photocatalysts in CO2 reduction are also presented.

Keywords

• CO2 reduction
• g‐C3N4
• photocatalysis
• solar‐to‐fuel conversion