•Anodic layer consists of external and inner layers in the presence of Mn2 +.•Mn2 + relieves corrosion of Pb-Ag anode in the presence of fluoride/chloride.•Mn2 + increases the thickness of inner layer in chloride containing solutions.•Anodic potential shows oscillation characteristic in the presence of Mn2 +.In this study, surface morphology, inner structure and phase composition of anodic layers on Pb-Ag anode in fluoride/chloride-containing H2SO4 solutions were investigated in the presence/absence of Mn2 +. Additionally, corrosion morphology of metallic substrate and anodic potential variation of Pb-Ag anodes were studied as well. The influence of Mn2 + on the anodic layer property and corrosion behavior of Pb-Ag anodes in fluoride/chloride-containing H2SO4 solutions was then clarified. The results revealed that in the presence of Mn2 +, anodic layer consisted of an external layer in MnO2/PbO2-PbSO4/MnO2 structure and an inner layer adhering to the metallic substrate. Due to the coverage of an external layer, the corrosion of metallic substrate was relieved by the presence of Mn2 + in fluoride/chloride-containing H2SO4 solution. As was demonstrated, Mn2 + decreased PbO2 concentration in the inner layer, especially in fluoride-containing solution. In the presence of Mn2 +, the anodic potential was higher than that in solutions without Mn2 + due to larger thickness and resistance of anodic layer. In addition, the anodic potential was characterized by oscillation in Mn2 +-containing solution, indicating low stability of anodic layer. Comparatively, the anodic layer formed in the presence of Mn2 + and chloride ion was more stable than that in solutions containing Mn2 + and fluoride ion.

Flexible Ga doped ZnO transparent conductive films were prepared on polymer substrates at room temperature by RF magnetron sputtering. The effect of the Ar flow rate is more important than that of r.f. power and sputtering pressure. The dependence of the structural, electrical, optical and adhesive properties of flexible Ga doped ZnO transparent conductive thin films on the Ar flow rate was investigated for the first time. When the Ar flow rate is 40 sccm, the residual stress is changed from compressive stress to tensile stress, indicating the crystallinity of the film is best. And the lowest square resistance of 7.9 Ω/sq. is obtained at the Ar flow rate of 40 sccm. Regardless of the Ar flow rate, the optical transmittance in the visible light of all the films is about 90%. The best adhesive behavior is obtained at the Ar flow rate of 40 sccm.

•Uniform Sb2O3 nanoprism arrays were firstly produced via chemical bath deposition.•The band structure of Sb2O3 was firstly obtained by the experiment and calculation.•The first photocurrent density of Sb2O3 thin films is 22 μA/cm2 at 1.23 V vs. RHE.•The Sb2O3 nanoprism arrays are intriguing for photoelectrochemical water splitting.Uniform Sb2O3 nanoprism arrays with high quality have been fabricated via a chemical bath deposition method. The first photocurrent density generated from the Sb2O3 thin films was 22 μA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE). The results illustrate the Sb2O3 thin films have potential applications in photoelectrochemical water splitting.Download high-res image (299KB)Download full-size image

•Bi2S3 TFs was produced by a template-free method without annealing.•Bi2S3 TFs has the photocurrent density of 0.8 mA/cm2 that is the highest to date.•The superior stability in aqueous solutions was confirmed.•The n-type Bi2S3 TF was a superb candidate for photoelectrochemical applications.Bi2S3 nanoparticles (NPs) in the form of thin films were deposited on fluorine doped SnO2 (FTO) coated conducting glass substrates by successive ionic layer adsorption and reaction (SILAR) at room temperature without annealing. The absorption coefficient could reach to the order of 106 cm−1 in the visible and NIR region, and the highest one was 5 × 106 cm−1. The highest photocurrent density of the synthesized Bi2S3 thin films (TFs) could maintain 0.8 mA/cm2 within 700 s under the light intensity kept at 30 mW/cm2. The photocurrent density is among the highest reported for any Bi2S3 photoelectrode without annealing to date. The photocurrent display little decrease during 4000 s of testing under illumination. The n-type Bi2S3 thin films display a reasonable photoactivity and photostablity under illumination and are thus promising candidates for photoelectrochemical applications.

The Cu2ZnSnS4 thin film was prepared by a facile solution method without vacuum environment and toxic substance. The formation mechanism of the film was studied by transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Raman scattering measurements. Through cyclic voltammetry and photo-electricity tests, the electrocatalytic activity of the prepared film as the counter electrode of dye-sensitized solar cell was also studied. The results show that the mixed precursor solution mainly consists of Cu2SnS3 nanoparticles and Zn ions. After 550 °C annealing process on the precursor film prepared from the mixed solution, Cu2ZnSnS4 thin film is obtained. Besides, it is found that the prepared Cu2ZnSnS4 thin film has the electrocatalytic activity toward the redox reaction of I3−/I− and the dye-sensitized solar cell with the prepared Cu2ZnSnS4 thin film as the counter electrode achieves the efficiency of 1.09%.

Porous β-Bi2O3 nanoplates were synthesized for the first time on FTO substrate via chemical bath deposition followed by annealing. They showed higher photoinduced current density than nonporous ones though the former possessed a larger band gap. The as prepared photoelectrodes exhibited superior stability in aqueous solutions. The results illustrate that the porous Bi2O3 nanoplate films have potential applications in photoelectrocatalysis.

An attempt was made to build up a thick and compact oxide layer rapidly by pre-treating the Pb-Ag-Nd anode in fluoride-containing H2SO4 solution. The passivation reaction of Pb-Ag-Nd anode during pre-treatment process was investigated using cyclic voltammetry, linear scanning voltammetry, environmental scanning electron microscopy and X-ray diffraction analysis. The results show that PbF2 and PbSO4 are formed near the potential of Pb/PbSO4 couple. The pre-treatment in fluoride-containing H2SO4 solution contributes to the formation of a thick, compact and adherent passive film. Furthermore, pre-treatment in fluoride-containing H2SO4 solution also facilitates the formation of PbO2 on the anodic layer, and the reason could be attributed to the formation of more PbF2 and PbSO4 during the pre-treatment which tend to transform to PbO2 during the following electrowinning process. In addition, the anodic layer on anode with pre-treatment in fluoride-containing H2SO4 solution is thick and compact, and its predominant composition is β-PbO2. In summary, the pre-treatment in fluoride-containing H2SO4 solution benefits the formation of a desirable protective layer in a short time.)

The corrosion and oxygen evolution behaviors of cast and rolled Pb–Ag–Nd anodes were investigated by metalloscopy, environmental scanning electron microscopy, X-ray diffraction analysis, and various electrochemical measurements. The rolled anode exhibits fewer interdendritic boundaries and a dispersed distribution of Pb–Ag eutectic mixtures and Nd-rich phases in its cross-section. This feature inhibits rapid interdendritic corrosion into the metallic substrate along the interdendritic boundary network. In addition, the anodic layer formed on the rolled anode is more stable toward the electrolyte than that formed on the cast anode, reducing the corrosion of the metallic substrate during current interruption. Hence, the rolled anode has a higher corrosion resistance than the cast anode. However, the rolled anode exhibits a slightly higher anodic potential than the cast anode after 72 h of galvanostatic polarization, consistent with the larger charge transfer resistance. This larger charge transfer resistance may result from the oxygen-evolution reactive sites being blocked by the adsorption of more intermediates and oxygen species at the anodic layer/electrolyte interfaces of the rolled anode than at the interfaces of cast anode.

•We presented a new cheaper molten salt system for electroless plating Pb on Al.•The metal bath process can amend the pores of Pb coating after electroless plating.•The metal bath process can regulate the composition and thickness of Pb coating.•Al/Pb grids have excellent performances and can be well used in lead-acid battery.In this paper, a lightweight Pb plated Al (Al/Pb) grid was prepared by molten salt electroless plating. The SEM and bonding strength test show that the lead coating is deposited with a smooth surface and firm combination. CV test shows that the electrochemical properties of Al/Pb electrodes are stable. 2.0 V single-cell flooded lead-acid batteries with Al/Pb grids as negative collectors are assembled and the performances including 20 h capacity, rate capacity, cycle life, internal resistance are investigated. The results show that the cycle life of Al/Pb-grid cells is about 475 cycles and can meet the requirement of lead-acid batteries. Al/Pb grids are conducive to the refinement of PbSO4 grain, and thereby reduce the internal resistance of battery and advance the utilization of active mass. Moreover, weight of Al/Pb grid is only 55.4% of the conventional-grid. In this way, mass specific capacity of Al/Pb-grid negatives is 17.8% higher and the utilization of active mass is 6.5% higher than conventional-grid negatives.

•The band gaps of CIGS thin films are well controlled by electrodeposition.•The effects of H2O2 on the electrodeposition of Cu(In,Ga)Se2 thin films have illustrated.•OH and OH− play an important role in high property CIGS thin films electrodeposition.The enhancement of Ga incorporation into the CIGS thin film by electrodeposition has been realized. One-step electrodeposition Cu(In,Ga)Se2 thin films under different hydrogen peroxide (H2O2) concentrations was investigated. The ratio Ga/(In + Ga) and characteristics of thin films were further modulated by adding H2O2 into electrolyte. The mechanism of the effects of H2O2 on electrodeposition Cu(In,Ga)Se2 thin films was illustrated using a schematic diagram. And this mechanism was proved by cyclic voltammograms, potentiostatic polarization, energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and Raman spectra. The films were found to have the same basic chalcopyrite structure of CuInSe2, and have the widen band gap (UV-VIS-NIR spectrophotometer) after adding H2O2 into the electrolyte. The evidence of Ga incorporation increment can be observed from the peak shift of Raman spectra and widen band gap.

A facile and cost-effective electrochemical approach was proposed for the first time to prepare a phosphorus-doped lead dioxide (P-PbO2) electrode on a lead substrate. This was achieved by introducing a pyrophosphate solution containing Cu2+, F− and peptone as essential additives. Such a novel P-PbO2 electrode exhibits a significantly improved electrocatalytic activity for the oxygen evolution reaction as compared to a traditional Pb/PbO2 electrode.

We report a facile electrochemical approach for the fabrication of phosphorus-doped (P-doped) PbO2–MnO2 composite electrodes with a microporous bicontinuous structure. Modification of such structures was achieved by controlling the MnO2 incorporation during an anodic co-deposition process. The results indicate the anodic co-oxidation of Pb2+ and Mn2+ yielded a P–(PbO2–MnO2) deposit with a flat, compact and smooth surface. Meanwhile, the anodic composite deposition of Pb2+ and MnO2 particles resulted in the bicontinuous (P–PbO2)–MnO2 composite with a well-defined microporous morphology. Tafel and EIS were used to characterize their electrocatalytic performances for the oxygen evolution reaction in a typical anodic water-splitting process. The results indicate that such a novel bicontinuous (P–PbO2)–MnO2 composite anode exhibits significantly improved electrocatalytic activity as compared to the P–PbO2 and P–(PbO2–MnO2) anodes. The oxygen evolution kinetics and possible reaction mechanism are further described.

A novel idea to inhibit the hydrogen evolution in activated carbon (AC) application in a lead-acid battery has been presented in this paper. Nitrogen group-enriched AC (NAC, mainly exists as pyrrole N) was prepared. Electrochemical measurements demonstrate that the hydrogen evolution reaction (HER) is markedly inhibited as the HER impedance increases significantly. What's more, the specific capacitance value of NAC is 142.5% higher than AC since the working window is extended. The use of NAC, instead of AC in an UltraBattery, can inhibit hydrogen evolution, and improve the battery's charge acceptance and charge retention ability.

•The Cu2ZnSnS4 ultrathin film CE was prepared in situ by the sol–gel method and showed a degree of transparence.•The dye-sensitized solar cell with the Cu2ZnSnS4 ultrathin film CE was the bifacially active transparent cell.•The Cu2ZnSnS4 ultrathin film CE showed better electrocatalytic activity than Pt CE.A Cu2ZnSnS4 (CZTS) ultrathin film counter electrode (CE) was prepared in situ by the sol–gel method. As the film was only 200 nm thickness, it showed a degree of transparence. The dye-sensitized solar cell (DSSC) with the prepared CE was the bifacially active transparent cell, which exhibited η of 5.63% and 1.60% corresponding to front- and back-side illumination respectively. It showed improved performance compared to DSSC with Pt CE, Electrochemical impedance spectroscopy (EIS) and Cyclic voltammetry (CV) measurements indicated the CZTS ultrathin film CE had a superior electrocatalytic activity than Pt CE.

•Cu2FeSnSe4 nanocrystals, which possessed a optical band gap value of 1.60±0.02 eV, were synthesized by a hot-injection method.•The Cu2FeSnSe4 thin film prepared by drop-casting nanocrystals ink shows clear and stable photo-electrochemical response.•Our work illustrates that Cu2FeSnSe4 nanocrystals have great potential application in the field of solar energy conversion.Cu2FeSnSe4 (CFTSe) nanocrystals have been synthesized by a hot-injection method. The structure of prepared CFTSe nanocrystals is determined by XRD, high resolution TEM image, and SAED pattern. The composition of the CFTSe nanocrystals is confirmed from the results of EDS and XPS. Results clearly prove the formation of CFTSe nanocrystals using the hot-injection method in this study. A band gap of 1.60±0.02 eV for CFTSe nanocrystals is obtained from the UV–vis–NIR data. Moreover, the corresponding CFTSe nanocrystals-film shows a clear photoresponse in photoelectrochemical measurement. Our work illustrates that CFTSe nanocrystals have potential application in the field of solar energy conversion.

Based on the basic principles of kinetics and some reasonable assumptions about the electrodeposition process, a dynamic model for metal selenide electrodeposition (kink site selected model) was constructed. This model is of universal significance in realizing the compositional prediction and dynamic behavior analysis of deposited films for different main salt concentration ratios and was applied to the ternary Cu–In–Se system. For CuInSe2 electrodeposition, in the Cu–Se system, the co-deposition of Cu and Se can be carried out within a large range of main salt concentration ratio; in the Cu–In system, the mole fraction of Cu in deposited thin films is always higher than that of Cu2+ in electrolyte, while in the In–Se system, the co-deposition of In and Se can be achieved only when the In3+ concentration is much higher than the H2SeO3 concentration. As for the compositional estimation of CuInSe2, the predictive results of our dynamic model agree well with the experimental data. It is then found that by correcting the difference of kink site selectivity constants caused by the change of deposition potential, the error of the predictive results can be reduced.

•N-doped p-type porous Bi2O3 nanoplates thin films (NPTFs) were firstly fabricated.•The samples exhibit a higher carrier concentration than the undoped one.•The mobility of N-doped porous Bi2O3 NPTFs closes to that of the undoped one.•The p-type behavior was originated from substitution at the O site with N.•The N-doped porous Bi2O3 NPTFs possessed a smaller bandgap than the undoped one.•The N-doped porous Bi2O3 NPTFs have the highest photocurrent density of 50 μA/cm2.N-doped p-type porous Bi2O3 nanoplates thin films (NPTFs) were firstly synthesized on FTO substrates through chemical bath deposition (CBD) followed by a thermal treatment process under a NH3 ambient. Hall effect results indicated the formation of p-type porous Bi2O3 NPTFs, and the best conductivity was achieved by N-doping with a higher carrier concentration, a lower resistivity, and an extremely close mobility compared with the undoped one. Mott–Schottky measurements further confirmed the p-type conductivity. The characteristics of optical and photoelectrochemical curves demonstrated that the N-doped porous Bi2O3 NPTFs were p-type with a smaller bandgap than the undoped n-type one, and the highest photocurrent density could reach 50 μA/cm2 under the light intensity kept at 30 mW/cm2. Thus N-doped p-type porous Bi2O3 NPTFs are promising candidates for photoelectrochemical applications.