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 fuels via hydrogen generation from water or CO2 reduction. Herein, a soft processable metal-organic hybrid material is developed and studied for photocatalytic activity towards H2 production and CO2 reduction to CO and CH4 under visible light as well as direct sunlight irradiation. A tetrapodal low molecular weight gelator (LMWG) is synthesized by integrating tetrathiafulvalene (TTF) and terpyridine (TPY) derivatives through amide linkages and results in TPY-TTF LMWG. The TPY-TTF LMWG acts as a linker, and self-assembly of this gelator molecules with ZnII ions results in a coordination polymer gel (CPG); Zn-TPY-TTF. The Zn-TPY-TTF CPG shows high photocatalytic activity towards H2 production (530 μmol g−1h−1) and CO2 reduction to CO (438 μmol g−1h−1, selectivity > 99%) regulated by charge-transfer interactions. Furthermore, in situ stabilization of Pt nanoparticles on CPG (Pt@Zn-TPY-TTF) enhances H2 evolution (14727 μmol g−1h−1). Importantly, Pt@Zn-TPY-TTF CPG produces CH4 (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.

Ultrafast carrier transport in ultrafine porous 2D polymers for the highly selective photocatalytic reduction of CO2to CH4

“…4b). 46 Under the dark reaction, D1M2-PC, D1M4-PC and D1M8-PC samples exhibited negligible current values, and once exposed to visible light irradiation, the current of D1M4-PC increased rapidly and its value was much higher than that of D1M2-PC and D1M8-PC. This result demonstrates the fast photoinduced carrier transfer in D1M4-PC, because the relatively compact π-conjugated structure makes it easy for the electrons of cyclotriphosphazene (donor) to transfer to S -triazine (acceptor), which eventually migrates to the immobilized CO 2 molecules.…”

Selective CO2-to-CO photoreduction over an orthophosphate semiconductor via the direct Z-scheme heterojunction of Ag3PO4 quantum dots decorated on SnS2 nanosheets

“…39,73 Moreover, the peak at 1692 cm À1 is associated with the formation of CO 2 À species. 74 Under light irradiation, Fig. 7b depicts that the intensity of the broad peaks (1300 to 1750 cm À1 ) chronologically decreases.…”

Double Confinement Hydrogel Network Enables Continuously Regenerative Solar‐to‐Hydrogen Conversion

“…This high photochemical stability was attributed to strong coordination between Pt NPs and sulfur-containing organic ligands inside the network. [17,22] Herein, the excellent continuous regeneration of PNPN@MA was owing to reversible bonding between Pt NPs and polymer chains. The greatly enhanced dynamics of Pt-SR under NIR light and stronger affinity of sulfur-ended polymer chains in contrast to EB or TEOA molecules were favorable for cleaning the surface poisoning, therefore reviving their catalytic activities.…”