Photocatalytic, electrocatalytic and photoelectrocatalytic conversion of methane to alcohol

The conversion of the greenhouse gas methane to value-added chemicals such as alcohols is a promising technology to mitigate environmental issue and the energy crisis. Especially, the sustainable photocatalytic, electrocatalytic and photoelectrocatalytic conversion of methane at ambient conditions is regarded as an alternative technology to replace with thermocatalysis. In this review, we summarize recent advances in photocatalytic, electrocatalytic and photoelectrocatalytic conversion of methane into alcohols. We firstly introduce the general principles of photocatalysis, electrocatalysis and photoelectrocatalysis. Then, we discuss the mechanism for selective activation of C-H bond and following oxygenation over metal, inorganic semiconductor, organic semiconductor, and heterojunction composite systems in the photocatalytic, electrocatalytic and photoelectrocatalytic methane oxidation in detail. Later, we present insights into the construction of effective photocatalyst, electrocatalyst and photoelectrocatalyst for methane conversion into alcohols from the perspective of band structures and active sites. Finally, the challenges and outlook for future designs of photocatalytic, electrocatalytic and photoelectrocatalytic methane oxidation systems are also proposed.