The much-needed renewable alternatives to fossil fuel can be achieved efficiently and sustainably by converting solar energy to fuels via hydrogen generation from water or CO₂ reduction. In this regard, a soft processable metal-organic hybrid semiconducting material has been developed and studied for photocatalytic activity towards H₂ production and CO₂reduction to CO and CH₄ under visible light and direct sunlight irradiation. A tetrapodal low molecular weight gelator (LMWG) has been synthesized by integrating tetrathiafulvalene and terpyridine moieties through amide linkages (TPY-TTF). The TPY-TTF LMWG acts as a linker, and self-assembly with Zn^II results in a charge-transfer (CT) coordination polymer gel (CPG); Zn-TPY-TTF. The Zn-TPY-TTF CPG shows high photocatalytic activity towards H₂ production (rate = 530 μmol g^-1h^-1) and CO₂ reduction to CO (rate = 438 μmol g^-1h^-1, selectivity >99%) regulated by charge-transfer interactions. Furthermore, in situ stabilization of Pt nanoparticle on CPG (Pt@Zn-TPY-TTF) exhibits remarkably enhanced H₂ evolution (rate = 14727 μmol g^-1h^-1). Importantly, Pt@Zn-TPY-TTF CPG produces CH₄(rate= 292 μmol g^-1h^-1, selectivity >97%) as CO₂ reduction product instead of CO. The real-time CO₂ reduction reaction is monitored by in situ DRIFT study, and the plausible mechanism is derived computationally. The photocatalytic activities of Zn-TPY-TTF CPG and Pt@Zn-TPY-TTF CPG were also examined under sunlight that displays appreciable performance toward H₂ evolution and CO₂ reduction.

Coordination polymer gel (CPG) based photocatalyst has been developed for visible/sun light driven H<sub>2</sub> evolution and CO<sub>2</sub> reduction. Notably, the product of CO<sub>2</sub> reduction can be switched from CO to CH<sub>4</sub> with >97% selectivity by tailoring CPG based hybrid photocatalyst.

Coordination polymer gel (CPG) based photocatalyst has been developed for visible/sun light driven H₂ evolution and CO₂ reduction. Notably, the product of CO₂ reduction can be switched from CO to CH₄ with >97% selectivity by tailoring CPG based hybrid photocatalyst.

Swapan Pati

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