Unexpected Insulating Polymer Maneuvered Solar CO₂‐to‐Syngas Conversion

Abstract

CO2 reduction to carbon feedstocks using heterogeneous photocatalysis technique has been deemed as an attractive means of addressing both deteriorating greenhouse effect and depletion of fossil fuels. Nevertheless, deficiency of accessible active sites on the catalyst surface, low CO2 adsorption rate, and short carrier lifetime retard the photocatalytic CO2 conversion into hydrocarbon fuels. In this study, the controllable construction of spatially separated directional charge transport pathways over multilayered heterostructured transition metal chalcogenides (TMCs) based photosystems for high‐performance photocatalytic CO2‐to‐syngas conversion are shown. In this scenario, ultrathin non‐conjugated insulating poly(diallyl‐dimethyl‐ammonium chloride) (PDDA) layer are intercalated in‐between TMCs and layered double hydroxide (LDH) and serve as an efficient electron transfer mediator, whilst LDH functions as a hole‐withdrawing regulator, both of which synergistically foster the spatial vectorial charge migration/separation over TMCs, thus endowing the TMCs/PDDA/LDH heterostructures with significantly boosted visible‐light‐driven photoactivity toward CO2 conversion into syngas. This study can inspire sparkling new ideas to realize fine tuning of charge motion for stimulating solar‐to‐fuel conversion.

Boosting Hydrogenation of Graphene Quantum Dot-Modified Photocatalysts: Specific Functionalized Modulation at Active Sites

“…These peaks shifted to lower binding energy levels after the deposition of PDDA, pGQDs, and rGQDs, indicating electron transfer from pGQDs/rGQDs to the HT framework . Furthermore, the peaks belonging to −NH– of GQDs in the HT/PDDA/pGQDs and HT/PDDA/rGQD hybrid systems exhibited an obvious shift (about 0.4 and 0.1 eV, respectively) to higher binding energy levels compared with those of individual GQDs, and the signals corresponding to NH 4 + in PDDA in the hybrid systems just slightly shifted to higher binding energy levels compared with those of HT/PDDA NPs, indicating strong electron interactions between GQDs and TiO 2 through the linking channel of the PDDA interlayer …”

“…36 Furthermore, the peaks belonging to −NH− of GQDs in the HT/PDDA/pGQDs and HT/PDDA/rGQD hybrid systems exhibited an obvious shift (about 0.4 and 0.1 eV, respectively) to higher binding energy levels compared with those of individual GQDs, and the signals corresponding to NH 4 + in PDDA in the hybrid systems just slightly shifted to higher binding energy levels compared with those of HT/PDDA NPs, 37 indicating strong electron interactions between GQDs and TiO 2 through the linking channel of the PDDA interlayer. 38 Photocatalytic Hydrogenation Performance of Various Catalysts. As a model reaction, the prepared HT/PDDA/ GQD catalysts were used for the photocatalytic hydrogenation of the 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) using isopropanol (IPA, 10 wt % in aqueous solution) as the hydrogen source (Figure 3a, and IPA will be oxidized to acetone).…”

Atomically precise thiolate-protected gold nanoclusters: current advances in solar-powered photoredox catalysis

“…Overall, we have summarized the latest developments in the growth mechanism and classication of gold NCs, and the photocatalytic mechanism of gold NC-based photosystems along with multiple photocatalytic applications including nonselective dye degradation, selective organic transformation, photocatalytic water splitting, photocatalytic CO 2 reduction and PEC water splitting. Although the progress on metal NCs and photocatalysis as well as photoelectrocatalysis is encouraging, [122][123][124][125][126][127][128][129][130][131][132][133][134][135][136][137][138][139] solar-driven gold NC-based photocatalysts are still a new research eld lacking in-depth study, and moreover, its photocatalytic applications are limited with solar energy conversion efficiency being far from satisfactory. From our perspective, the following several challenges should be highlighted in future research work.…”

Transition Metal Chalcogenides Quantum Dots: Emerging Building Blocks toward Solar-to-Hydrogen Conversion

“…109 Generally, small molecules serve as natural ligands for charge migration in photocatalytic system, which can realize the compression of interparticle spacing and reinforce the interaction of electronic coupling between QDs. 110 In this case, well-designed surface ligand engineering is essential for maximizing the quantum yield and maintaining high stability of QDs. For example, Yu et.…”

“…In preparation of colloidal semiconductors, precursors react in the presence of a stabilizing agent (surface ligand) that is capable of restricting the growth of nanocrystal and keeping the size within the quantum confinement range as estimated by eq presented by Griffiths. , For instance, photoinduced QDs can be functionalized with hydrophilic and thiol-based ligands, including cysteamine (CA), dihydrolipoic acid (DHLA), D-penicillamine (DPA), and 3-mercaptopropionic acid (MPA) to inhibit aggregation and induce solubility in aqueous solution (Figure a) . Generally, small molecules serve as natural ligands for charge migration in photocatalytic system, which can realize the compression of interparticle spacing and reinforce the interaction of electronic coupling between QDs . In this case, well-designed surface ligand engineering is essential for maximizing the quantum yield and maintaining high stability of QDs.…”