Charge-Transfer Regulated Visible Light Driven Photocatalytic H2 Production and CO2 Reduction in Tetrathiafulvalene Based Coordination Polymer Gel

Abstract

The much-needed renewable alternatives to fossil fuel can be achieved efficiently and sustainably by converting solar energy to solar 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 CO2 reduction to CO and CH4 under visible light and direct sunlight irradiation. A tetrapodal low molecular weight gelator is synthesized by integrating tetrathiafulvalene and terpyridine through amide linkage (TPY-TTF). The TPY-TTF acts as a linker and by self-assembly with ZnII results in a charge-transfer (CT) coordination polymer gel (CPG); Zn-TPY-TTF. The Zn-TPY-TTF shows impressive 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 interaction. Furthermore, in-situ stabilization of Pt nanoparticles to CPG (Pt@Zn-TPY-TTF) exhibits remarkably enhanced H2 evolution (rate =14727 μmol g-1h-1). Importantly, Pt@Zn-TPY-TTF modulate the CO2 reduction from CO to CH4 (rate = 292 μmol g-1h-1, selectivity >97%). Real-time CO2 reduction reaction is monitored by in-situ DRIFT study and subsequent plausible mechanism is derived computationally. The photocatalytic activity of Zn-TPY-TTF and Pt@Zn-TPY-TTF composite was also examined under sunlight that display excellent H2 evolution and CO2 reduction.

Engineering of PMo12@NiCo-LDH compositevia in situencapsulation-reassembly strategy for highly selective photocatalytic reduction of CO2to CH4

“…60 In addition, the characteristic vibration of CO* intermediates displayed a weak peak at 2065 cm −1 . It was considered that the small amount of CO* generated in CO 2 PR was readily converted into CH 3 O* and CHO* intermediates to form CH 4 rather than desorbing from PMo 12 @NiCo-LDH and generating CO, 61…”

Self-Templated Conversion of a Self-Healing Metallogel into an Active Carbon Quasiaerogel: Boosting Photocatalytic CO2 Reduction by Water

“…36−38 In this context, only a handful of literature is available for CO 2 reduction into fuels and value-added chemicals based on metal−organic gel catalysts; for example, Maji and co-workers reported zinc-and ruthenium-mediated metal−organic gel-based photocatalysts for CO 2 reduction into CO and CH 4 . 22,24 Lan and co-workers reported a copperhydrogel-derived catalyst for CO 2 conversion into C 2 H 4 and CH 4 . 39 Su et al reported an iron−sulfur cluster-containing hydrogel for CO 2 reduction into formate.…”