•High Faradic efficiency for CO (95%) is achieved on bulk Ag electrode.•The addition of DTAB contributes to enhanced CO2 conversion efficiency.•Hydrogen evolution is suppressed by the adsorbed DTAB on Ag electrode.Electrochemical CO2 reduction provides a desirable pathway to convert greenhouse gas into useful chemicals. It is a great challenge to reduce CO2 efficiently in aqueous solution, especially on commercial bulk metal electrodes. Here, we report substantial improvement in CO2 reduction on bulk silver electrode through the introduction of ionic surfactant in aqueous electrolyte. The hydrogen evolution on the electrode surface is greatly suppressed by the surfactant, while the catalytic ability of silver towards CO2 reduction is maintained. The Faradaic efficiency for CO is greatly enhanced from 50% to 95% after the addition of this low-cost surfactant. This study may provide new pathways towards efficient CO2 reduction through the inhibition of proton reduction.Download high-res image (102KB)Download full-size image

A low-cost zinc catalyst, prepared by a facile electrochemical strategy, produces CO with up to 93% Faraday efficiency in aqueous NaCl solution. The catalytic activity of the Zn catalyst is demonstrated to be dependent on both the morphology of the catalyst and the catholyte anions.

A green synthetic strategy is developed to prepare PtxCuy/C catalyst in the absence of any capping ligands. Commercial Pt/C catalyst is used as the platinum precursor, and the Pt nanoparticles on the carbon act as a catalyst for the reduction of copper (II) precursors by hydrazine, which leads to the confined deposition of Cu on the Pt nanoparticles. The newly deposited Cu diffuses into the Pt nanoparticles to form PtxCuy alloy nanoparticles under hydrothermal conditions. The as-synthesized PtxCuy/C exhibits superior activity compared with commercial Pt/C towards the electro-oxidation of methanol. The results highlight the significance of alloy formation as an approach to improve the activity of commercial Pt/C catalyst.

•Nanostructured Cu–Au alloy was tested as electro-catalyst for CO2 reduction.•Au component contributed greatly to the conversion of CO2 to alcohols.•Faradic efficiency of CH3OH on nano Cu63.9Au36.1 was 19 times that on Cu plate.Electrochemical reduction of CO2 in an aqueous 0.5 M KHCO3 solution is studied by use of novel nanostructured Cu–Au alloys, which are prepared through electrochemical deposition with a nanoporous Cu film (NCF) as template. Linear voltammetry results show that the as-synthesized Cu–Au alloys exhibit obvious catalysis towards electrochemical reduction of CO2. Further analysis of products reveals that faradic efficiencies of alcohols (methanol and ethanol) are greatly dependent on the nanostructures and compositions of Cu–Au alloys. It is expected that this work could provide new insight into the development of powerful electrocatalysts for reduction of CO2 to alcohols.

•A novel synthetic route for high-surface-area bismuth (HSA-Bi) is developed.•HSA-Bi shows superior activity towards reduction of CO2 than commercial Bi.•Reduction potential of CO2 is obviously lowered on HSA-Bi.•High Faradic efficiency (92%) of formate is obtained on HSA-Bi catalyst.•Stability and high current density are maintained during continuous electrolysis.In this paper, we present our work on electrochemical reduction of CO2 under ambient conditions using a high-surface-area bismuth (HSA-Bi) catalyst, which is fabricated by electrochemical reduction of BiOCl nanosheets. This HSA-Bi catalyst exhibits surprising selectivity towards reduction of CO2 to formate with a high Faradic efficiency (~ 92%). In addition, the activity of this catalyst remains stable during long-time electrolysis and maximum current density of ~ 3.7 mA mg− 1 could be obtained. The high activity is attributed to the special nanostructure of catalyst, as indicated by lower overpotential of CO2 reduction on HSA-Bi than that on commercial Bi powder. The HSA-Bi catalyst is believed to be a promising catalyst for further application.

Nanoporous Cu film (NPCF) is fabricated on Cu plate by a novel electrochemical dealloying process in dilute HCl solution. The as-synthesized low-cost NPCF/Cu is used as anode in electro-oxidation of hydrazine for the first time and exhibits superior catalytic activity. The current density from hydrazine oxidation on NPCF is much higher than that on smooth copper. In addition, the NPCF electrode shows unexpected higher stability than Cu nanoparticles in similar size. It is believed that this low-cost NPCF electrode possesses potential application in the hydrazine fuel cell or other catalytic fields.Graphical abstractHighlights► Nanoporous Cu formed by LSV dealloying of surface Cu–Zn alloy in short time. ► Lower onset oxidation potential of hydrazine on nanoporous Cu than smooth Cu. ► Superior activity of nanoporous Cu toward oxidation of hydrazine. ► Higher stability of nanoporous Cu than Cu nanoparticles.

BiOI nanoflake arrays were fabricated on the ITO/PET substrate by modified successive ionic layer adsorption and reaction (SILAR) method and served as p-type semiconductor materials for flexible solar cell. The morphologies of BiOI nanoflakes deposited on ITO/PET after different cycles of SILAR were analyzed and these nanoflakes were all in single crystalline structure. The growth process of BiOI nanoflake arrays was discussed and corresponding formation mechanism was proposed. The assembled dye-free BiOI/ITO/PET solar cell exhibited superior photovoltaic performance than that on FTO/glass substrate. In addition, the adhesion of BiOI to ITO/PET substrate was superior and the photocurrent of flexible solar cell was stable after bending test.Graphical abstractHighlights► A dye-free flexible solar cell based on p-type BiOI nanoflake arrays. ► Oriented attachment was demonstrated to dominate the formation of BiOI nanoflakes. ► Solar cell possessed good stability of photocurrent as well as flexibility. ► A maximum IPCE of ∼6.5%.

We demonstrate that appropriate Pt loading could significantly enhance the ability of TiO2 nanorods array thin film (TNTF) electrode to photoelectrochemically split water under solar light. The TiO2 nanorods array thin film was directly grown on fluorine-doped tin oxide glass through hydrothermal reaction. And platinum (Pt) nanoparticles were deposited uniformly on the surface of TiO2 nanorods by a convenient sputtering method. The Pt-loaded TNTF sample was highly stable during the photoelectrochemical water splitting process. Its activity did not decrease after 50 continuous potential scans. This study reveals that the Pt loaded TiO2 nanorods array thin film electrode is promising for the photoelectrochemical water splitting to generate hydrogen.Graphical abstractHighlights► Pt nanoparticles are deposited uniformly by convenient sputtering method. ► Amount of Pt loading affects greatly the photoelectrochemical water splitting. ► 20 seconds’ Pt sputtering gives the best results. ► The activity of Pt-loaded TNTF electrode is highly stable.

Prussian blue-modified nanoporous gold film (PB-NPGF) electrode was fabricated in this study. The fabrication was realized through electrodeposition of Prussian blue nanoparticles on the skeleton of a nanoporous gold film electrode without destroying the porous structure of NPGF electrode. The resulting PB-NPGF composite electrode showed very high electrocatalytic activity, repeatability, and stability to the reduction of H2O2. For instance, its activity was about twenty times that of the PB-modified polished gold electrode. More importantly, the sensitivity of the PB-NPGF composite electrode reaches as high as 10.6 μA μM−1 cm−2. This PB-NPGF composite electrode is very promising in the fields of catalysis, analysis, and so on.

A low-cost zinc catalyst, prepared by a facile electrochemical strategy, produces CO with up to 93% Faraday efficiency in aqueous NaCl solution. The catalytic activity of the Zn catalyst is demonstrated to be dependent on both the morphology of the catalyst and the catholyte anions.