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One of the key challenges in artificial photosynthesis is to design a photocatalyst that can bind and activate the CO molecule with the smallest possible activation energy and produce selective hydrocarbon products. In this contribution, a combined experimental and computational study on Ni-nanocluster loaded black TiO (Ni/TiO ) with built-in dual active sites for selective photocatalytic CO conversion is reported. The findings reveal that the synergistic effects of deliberately induced Ni nanoclusters and oxygen vacancies provide (1) energetically stable CO binding sites with the lowest activation energy (0.08 eV), (2) highly reactive sites, (3) a fast electron transfer pathway, and (4) enhanced light harvesting by lowering the bandgap. The Ni/TiO photocatalyst has demonstrated highly selective and enhanced photocatalytic activity of more than 18 times higher solar fuel production than the commercial TiO (P-25). An insight into the mechanisms of interfacial charge transfer and product formation is explored.

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An imide-functionalized material, poly(oxyethylene)-segmented polymer, was synthesized from the reaction of poly(oxyethylene) diamine of 2000 g mol(-1) M(w) and 4,4'-oxydiphthalic anhydride and used to disperse hybrid nanomaterials of platinum nanoparticles and multi-wall carbon nanotubes (PtNP/MWCNT). The composite material was spin-coated into film and further prepared as the counter electrode (PtNP/MWCNT-CE) for a dye-sensitized solar cell (DSSC). The short-circuit current density (J(SC)) and power-conversion efficiency (eta) of the DSSC with PtNP/MWCNT-CE were found to be 18.01 +/- 0.91 mA cm(-2) and 8.00 +/- 0.23%, respectively, while the corresponding values were 14.62 +/- 0.19 mA cm(-2) and 6.92 +/- 0.07% for a DSSC with a bare platinum counter electrode (Pt-CE). The presence and distribution of PtNP/MWCNT on the CE were characterized by using scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The attachment of PtNPs on MWCNTs was observed by transmission electron microscopy (TEM). Cyclic voltammetry (CV), incident-photo-to-current efficiency (IPCE) and electrochemical impedance spectra (EIS) were correlated to explain the efficacy of this nanocomposite system

A hybrid of polymer-dispersed multi-walled carbon nanotubes (MWCNT) was utilized in networking with the conventional composition of gel electrolyte in dye-sensitized solar cells (DSSCs) to purposely enhance the cell efficiency. The requisite polymer as the dispersant is structurally tailored for its functionalities consisting of poly(oxyethylene)-segmented amides and imides. The existence of the dispersant is multi-functional for first de-bundling the originally aggregated MWCNT and subsequently networking with the conventional gel electrolyte, poly(vinylidene fluoride-cohexafluoropropylene) (PVDF-HFP)/LiI system. The gel electrolyte comprised of only 0.25 wt% MWCNT/POEM in the finely dispersed state was fabricated into a quasi-solid-state DSSC which showed high power-conversion efficiency (h) of 6.86% and short-circuit current density (J SC ) of 15.3 mA cm À2 at the test of 100 mW cm À2 irradiation. The DSSC efficiency was significantly improved from the use of the unmodified gel electrolyte having the values of J SC ¼ 9.6 mA cm À2 and h ¼ 4.63%. The enhancement was further confirmed by the electrochemical impedance spectra analyses for the lowest Warburg resistance (R w ). The fine dispersion of MWCNT in the polymeric dispersant was characterized by UV-Vis, TEM, FT-IR and DSC. The finding indicates the role of MWCNT for homogenizing the amorphous PVDF-HFP and facilitating the diffusion state of I À /I 3 À ion pairs in this electrolyte system.