Visible light-driven oxidant-free dehydrogenation of alcohols in water using porous ultrathin g-C3N4 nanosheets

Graphitic carbon nitride (g-C3N4) is a fascinating photocatalyst for solar energy utilization in photo-catalysis. Nevertheless, it often suffers from moderate photo-catalytic activity due to its low specific surface area and fast recombination rate of photogenerated electrons upon photo-excitation. Herein, we overcome the bottlenecks by constructing a porous g-C3N4 nanosheet (PCNS) through a simple thermal oxidation etching method. Benefited from its porous layer structure, the obtained PCNS exhibits large specific surface area, efficient separation of photogenerated charge carriers, as well as high exposure of active sites. As a result, it is robust and universal in visible light-driven dehydrogenation of alcohols in water under oxidant-free condition. Almost quantitative yields (>99%) of various valuable carbonyl compounds were obtained over PCNS, while bulk g-C3N4 was far less efficient. Moreover, the photo-catalyst was highly stable and could be facilely recovered from the aqueous system for efficient reuse. The easy preparation and excellent performance made PCNS a promising and competitive photocatalyst for the solar applications.