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Hollow hierarchical structure Co0.85Se as efficient electrocatalyst for the triiodide reduction in dye-sensitized solar cells
摘要： The exploration of nonprecious metal-based electrocatalysts with high efficiency for the triiodide reduction is critical for the practical applications of the dye-sensitized solar cells. Herein, we develop a facile one-step hydrothermal method to synthesize hollow hierarchical structure Co0.85Se. Under the methanol-water reaction system, the product named as hollow hierarchical structure Co0.85Se-M has the largest specific surface area (215.36 m2 g?1) and the best crystallinity than other products obtained from other alcohol-water reaction systems. When this electrocatalyst is applied as a counter electrode for the dye-sensitized solar cells, it exhibits a small peak-to-peak separation (Epp, 97 mV) for the reduction of I3?/I? redox couple. It is found that the catalytic activity of Co0.85Se is closely dependent on the crystallinity. Moreover, the reactivity pathway is identified by density functional theory, which confirms that triiodide is reduced to iodide ion on Co0.85Se with a smaller energy barrier (～0.65 eV) than on Pt (～1.18 eV). Both experimental and theoretical results demonstrate Co0.85Se-M as an ideal counter electrode material for the dye-sensitized solar cells with a higher power conversion efficiency (8.76%) than Pt counter electrode (7.20%).
关键词： Dye-sensitized solar cells,Hollow hierarchical structure,Cobalt selenides,Electrocatalytic activity,Triiodide reduction
更新于2025-11-21 11:03:13
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g-C3N4 nanosheets functionalized silicon nanowires hybrid photocathode for efficient visible light induced photoelectrochemical water reduction
摘要： We report the fabrication of hybrid Si nanowires @ g-C3N4 nanosheets based photocathode using metal assisted chemical etching and facile liquid exfoliated process. The g-C3N4 nanosheets on Si nanowires form hybrid heterojunction photocathode, which exhibits an enhanced photon induced water reduction activity enabling higher photocurrent density of 22 mA cm?2 with applied bias photocurrent conversion efficiency of 4.3% under visible light irradiation. The onset potential of cathodic photocurrent is positively shifted from 41 to 420 mV vs. RHE with the short circuit current density, Jsc of 0.50 mA cm?2 owing to superior charge transport in hybrid photocathode as compared to pristine Si nanowires for hydrogen evolving reaction at pH～7. The electrochemical impedance spectroscopy measurement elucidates the interface layer of g-C3N4 nanosheets form hybrid heterojunction with Si nanowires that result significant increment in solar water reduction activity owing to low charge transferred resistance with high life time of excited electrons in conduction band. This strategy may open to design a new low cost stable hybrid heterostructure photocathode for solar induced water reduction.
关键词： Solar water reduction,Si nanowires,Photocathode,g-C3N4 nanosheets,Interface
更新于2025-11-21 11:01:37
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A cyanide-bridged di-manganese carbonyl complex that photochemically reduces CO <sub/>2</sub> to CO
摘要： A cyanide-bridged di-manganese carbonyl complex that photochemically reduces CO2 to CO? Hsin-Ya Kuo, Tia S. Lee, An T. Chu, Steven E. Tignor, Gregory D. Scholes and Andrew B. Bocarsly* Manganese(I) tricarbonyl complexes such as [Mn(bpy)(CO)3L] (L = Br, or CN) are known to be electrocatalysts for CO2 reduction to CO. However, due to their rapid photodegradation under UV and visible light, these monomeric manganese complexes have not been considered as photocatalysts for CO2 reduction without the use of a photosensitizer. In this paper, we report a cyanide-bridged di-manganese complex, {[Mn(bpy)(CO)3]2(μ-CN)}ClO4, which is both electrocatalytic and photochemically active for CO2 reduction to CO. Compared to the [Mn(bpy)(CO)3CN] electrocatalyst, our CN-bridged binuclear complex is a more efficient electrocatalyst for CO2 reduction using H2O as a proton source. In addition, we report a photochemical CO2 reduction to CO using the dimanganese complex under 395 nm irradiation.
关键词： electrocatalyst,cyanide-bridged,photochemical reduction,CO2 reduction,di-manganese,photocatalyst,carbonyl complex
更新于2025-11-19 16:56:42
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Sensitized photochemical CO2 reduction by hetero-Pacman compounds linking a Re(I) tricarbonyl with a porphyrin unit
摘要： The hetero-Pacman architecture places two different metal coordination sites in close proximity, which can support efficient energy and/or electron transfer and allow for cooperative activation of small molecules. Herein, we present the synthesis of dyads consisting of a porphyrin unit as photosensitizer and a rhenium unit as catalytically active site, which are held together by the rigid xanthene backbone. Mononuclear [(NN)Re(CO)3(Cl)] complexes for CO2 reduction where NN represents a bidentate diimine ligand (e.g. bipyridine or phenanthroline) lack light absorption in the visible region, resulting in poor photocatalysis upon illumination with visible light. In order to improve their visible light absorption, we have focused on the incorporation of a strongly absorbing free base or zinc porphyrin unit. Resulting photocatalytic experiments showed a strong dependence of catalytic performance on both the type of photosensitizer and also the excitation wavelengths. Most notably, the intramolecular hetero-Pacman system containing a zinc porphyrin unit showed much better catalytic activity in the visible region (excitation wavelengths >450 nm) than the free base version, the corresponding mononuclear rhenium compound or an intermolecular system comprised of a 1:1 mixture of the mononuclear analogues.
关键词： photocatalysis,CO2 reduction,electron transfer,porphyrin,rhenium
更新于2025-11-19 16:56:35
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Probing the Role of Nickle Dopant in Aqueous Colloidal ZnS Nanocrystals for Efficient Solar-Driven CO2 Reduction
摘要： Photocatalytic CO2 reduction reaction (CO2RR) on a heterogeneous catalyst offers the possibility for CO2 abatement and emerges as a promising avenue for renewable carbonaceous fuels production at ambient temperature and pressure using solar light as the sole energy input. Here, we report a newly aqueous colloidal comprised of monodispersed Ni-doped ZnS (ZnS:Ni) nanocrystals as excellent visible-light-responsive photocatalysts for CO2RR into formate. The wavelength-dependent quantum yield shows a significant contribution of Ni doping for visible light absorption. A high selectivity (>95%) of HCOOH production and a remarkable quantum efficiency of 59.1% at 340 nm and 5.6 % at 420 nm are obtained over ZnS:Ni (0.1 %) colloidal nanocrystals modified by Cd2+. The abundant sulfur vacancies and extended visible light absorption of the constructed colloidal ZnS:Ni nanocrystals contribute to the prominent performance for CO2RR. However, excessive doping of Ni does not guarantee an increase of photocatalytic CO2RR due to a diminish of sulfur vacancy. The regulation of sulfur vacancies by Ni doping and their interplay on photocatalytic CO2RR activity are presented and discussed. This work provides an in-depth insight of the role of dopant on vacancy modulation in photocatalyst beyond light absorption and a guidance for design of the potential photocatalyst for CO2RR.
关键词： CO2 reduction,vacancy,photocatalysis,doping,ZnS
更新于2025-11-19 16:51:07
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Zinc Rhodium Oxide and Its Possibility as a Constituent Photocatalyst for Carbon Dioxide Reduction using Water as an Electron Source
摘要： We evaluated the potential of zinc rhodium oxide (ZnRh2O4) as a carbon dioxide (CO2) reduction photocatalyst with the aid of triethanolamine (TEOA) as an electron donor and demonstrated that ZnRh2O4 was able to reduce CO2 to carbon monoxide (CO) under infrared light. Gold (Au) loading onto ZnRh2O4 greatly enhanced the CO2 reduction activity. Also, CO2 reduction was examined over a composite of ZnRh2O4 and bismuth vanadium oxide (Bi4V2O11) with inserted Au (ZnRh2O4/Au/Bi4V2O11) using H2O as the electron source, which led to the successful evolution of CO.
关键词： Carbon monoxide,Methane,Triethanolamine,Gold,Carbon dioxide reduction,Zinc rhodium oxide
更新于2025-11-19 16:51:07
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Lewis acid activated CO <sub/>2</sub> reduction over a Ni modified Ni–Ge hydroxide driven by visible-infrared light
摘要： Improvement of light harvesting and reaction kinetics is of great importance for achieving efficient solar-driven CO2 reduction. Here, a Ni modified low-crystalline Ni–Ge containing hydroxide with Lewis acid sites was synthesized in highly reductive NaBH4 solution and exhibited 9.3 μmol gcat.?1 h?1 CO and 3.5 μmol gcat.?1 h?1 CH4 generation rates under visible light irradiation, and even achieved a 3.8 μmol gcat.?1 h?1 CO evolution under infrared light irradiation. The wide-spectrum light harvesting resulted from the light absorption from the localized surface plasmonic resonance of Ni nanoparticles. In addition, the Lewis acid can activate CvO bonds to decrease the kinetic barriers of CO2 reduction. The design concept that rationally combines the advantages of expanding the spectral response and activating CO2 may offer a new strategy for efficient solar energy utilization.
关键词： visible-infrared light,plasmonic effect,Lewis acid,CO2 reduction,photocatalyst
更新于2025-11-19 16:51:07
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Thiourea-assisted coating of dispersed copper electrocatalysts on Si photocathodes for solar hydrogen production
摘要： Photoelectrochemical water splitting can convert solar energy into clean hydrogen energy for storage. It is desirable to explore non-precious electrocatalysts for practical applications of a photoelectrode in a large scale. Here, we developed a facile spin-coating and in-situ photoelectrochemical reduction method to prepare a dispersed Cu electrocatalyst on a Si photocathode, which improves the performance remarkably. We find that thiourea in the precursor solution for spin-coating plays an important role in obtaining dispersed Cu particles on the surface of a Si photoelectrode. With thiourea in the precursor, the Cu/Si photocathode shows higher performance than the one without thiourea. Moreover, the Cu/Si photocathode also indicates good stability after 16 h illumination.
关键词： In-situ photoelectrochemical reduction,Cu electrocatalyst,Thiourea,Hydrogen evolution reaction
更新于2025-11-19 16:51:07
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Wafer-Scale Si Nanoconed Arrays Induced Syngas in the Photoelectrochemical CO2 Reduction
摘要： Photoelectrochemical (PEC) CO2 reduction offers a promising way to carry out the CO2 sequestration and develop the carbon-neutral technology. Doped Si is by far one of the most technologically important semiconductors with high conductivity and narrow bandgap, potential for CO2 reduction. However, the previous reports on PEC CO2 reduction over Si electrodes were not involved with many nanostructures. Syngas, a kind of chemical feedstocks and a crucial intermediate for hydrocarbon fuels, is highly demanded for industry. Herein, we used a wafer-scale nanoconed Si arrays substrate to load the metallic nanoparticles (Au and Cu). Effective PEC CO2 reduction into syngas was achieved in the aqueous solution with no sacrificial reagents. In contrast, planar Si seldom generated CO under the same reactant environment. Our finding deepens the comprehension of PEC CO2 reduction over the nanostructured materials and gives an inspiration for rational design of the PEC catalysts towards solar-to-chemical conversion.
关键词： Si,photoelectrochemical (PEC),CO2 reduction,nanostructure,syngas
更新于2025-11-19 16:51:07
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A facile synthesis of palladium encased Ag nanowires and its effect on fluorescence and catalysis
摘要： A facile polyol synthetic route was designed to prepare an ultra thin Pd nano sheath over Ag nanowires (NWs) forming metal-metal core–shell nanocomposites. Here we report the one pot synthesis of Pd assembly onto growing Ag NWs. Pd salts were reduced over varied time intervals during the growth process of the Ag NWs. The Pd salt was introduced after 20, 30- and 40-minutes to the growing Ag NWs. The product was designated as Ag@Pd 20, 30, and 40 on basis of introducing interval. The morphology and constituents of each product was observed using SEM coupled with EDX. XRD was employed to characterize composite material. UV-Visible was used to determine the SPR of each material along with the pure Ag NWs and palladium nanoparticles. Similarly, ?uorescence of each product was characterized using PL spectrophotometer, which was correlated with core and sheath. Finally, the catalytic reduction of nitrophenol into amino phenol by ultra thin sheet of Pd of each product was investigated and reaction order was ascertained.
关键词： core@shell,?uoroscence,catalytic reduction,Pd-Ag composites
更新于2025-11-19 16:46:39