Photocatalytic coproduction of hydrogen peroxide and Aldehydic/Keto acid on carbon nitride

Photocatalytic H2O2 production is emerging as an alternative technology to contribute H2O2-based advanced oxidation applications. However, the present reaction systems rarely consider the selective oxidation of sacrificial agent along with oxygen reduction reaction. Herein, we design a reaction system by using hydroxycarboxylic acids as additives to boost photocatalytic H2O2 production. More importantly, hydroxycarboxylic acids could simultaneously be dehydrogenated into aldehydic/keto acids with high selectivity. Lactic acid as one of the typical hydroxycarboxylic acids reveals the feasibility of this hypothesis, delivering 6.56 mM/h of H2O2 generation along with > 70 % pyruvic acid selectivity. The universality of this reaction system is demonstrated by using other hydroxycarboxylic acids. This works sheds new light on coupling H2O2 generation with value-added chemicals production by mild photocatalytic approach.