Employing photo-energy to drive the desired chemical transformation has been a long pursuing subject. The development of homogeneous photoredox catalysts in radical coupling reactions has been truly phenomenal, however with...

Although the development of C–H functionalization methods has enlightened many reactivities in chemistry, the direct functionalization of unactivated C–H bonds, which are particularly common in petroleum compounds, is still faced with great difficulty. Herein, we describe a photocatalytic approach that allows direct methylation of unactivated sp3 and sp2 C–H bonds using methanol as the methylation reagent, with gallium nitride as a powerful yet robust catalyst. Mechanistic studies suggested that the methanol is dehydrated into methyl carbene intermediate via a bimolecular mechanism.

Summary Ammonia is one of the most important bulk chemicals in modern society. However, the highly energy-extensive contemporary industrial production of ammonia was developed in the early 20th century and requires extensive heating of highly pressurized flammable hydrogen gas, whose global production still relies heavily on non-sustainable petroleum. The development of “sustainable” nitrogen fixation process represents a grand aspirational chemical pursuit concerning our future human well-being. Herein, we report an ultra-stable nitride-based photosensitizing semiconductor that enables efficient, sustainable, and mild photochemical nitrogen fixation. The catalyst exhibits strong chemisorption of nitrogen and enables immediate electron donation from its surface vacancy to nitrogen. In addition, it was also demonstrated that the nitride-based semiconductor possesses the potential to minimize electron-hole recombination.