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A p-n heterojunction based Ni3V2O8@g-CN nanocomposite acts as photocatalyst for selective activation of inert C(sp3)–H bonds of cyclohexane to form KA-oil.

Among photocatalytic semiconductors, minimization of recombination rate of photogenerated charge carriers to enhance their utilization via band structure engineering would be an effective approach ...

The selective conversion of 5-hydroxymethyfurfural (HMF), a biomass-derived platform molecule, to value added chemicals can ease the burden on petroleum-based fine chemical synthesis. The active contribution of renewable energy sources along with low cost, environmental friendliness, and a simple reaction system must be adopted for better sustainability. In this context, photocatalytic selective hydrogenation of HMF to 2,5-bis(hydroxymethyl)furan (BHMF) was achieved over P25 titania nanoparticles without chemical squander. Simultaneously the photo-oxidation of p-methoxybenzyl alcohol (MeOBA) to p-methoxybenzaldehyde (MeOBaL), similar to biomass-derived vanillin, was carried out, abolishing the need of additional redox reagents. This system put forward the competent employment of photogenerated excitons for the valorization of lignocellulosic biomass to fine chemicals, which is an urgent requirement for sustainable chemical synthesis.

In this study, we have demonstrated photocatalytic H2 evolution by water splitting coupled with biomass derived 5-(hydroxymethyl) furfural (HMF) oxidation to a more valued platform chemical, 2,5-diformylfuran (DFF), under visible light using porous carbon nitride (SGCN) for the first time. Simultaneously, a H2 production rate of 12 μmol h−1 m−2 was obtained with a DFF yield of 13.8% with >99% selectivity after 6 h under visible light. The selectivity of DFF was maintained >99% even after longer runs (48 h) with an improved DFF yield of 38.4% and H2 production rate of 36 μmol h−1 m−2. In addition, a H2 production rate of 6.2 μmol h−1 m−2 with 0.15 light-to-fuel efficiency (LFE) and DFF (7.2% yield) were obtained under natural sunlight after 6 h. Thus, this study describes an effective way to utilize both photogenerated electrons and holes for simultaneous H2 production by water splitting and biomass derived HMF oxidation to DFF, respectively, under natural sunlight.

Metal-free organic polymer photocatalysts have attracted dramatic attention in the field of visible light-induced hydrogen evolution reaction (HER). Herein, we showed a polymeric O-linked heptazine polymer (OLHP) decorated with S, N co-doped graphene quantum dots (S,N-GQDs) as a photosensitizer to generate hydrogen upon quantum dot sensitization. Both of these heptazine-based systems show effective photosensitization with strong π–π interactions and enhanced photocatalytic H2 generation (24 times) as metal-free systems. Electrochemical impedance and optical measurements show effective charge transfer kinetics with decreased charge recombination, which is responsible for the enhanced photocatalytic activity. As a result, a significant high apparent quantum yield (AQY) with highest value of 10.2% was obtained for our photocatalyst OLHP/S,N-GQD10.