Zeolitic-imidazolate frameworks-derived Co3S4/NiS@Ni foam heterostructure as highly efficient electrocatalyst for oxygen evolution reaction

Transition metals sulfide-based nanomaterials have recently received significant attention as a promising cathode electrode for the oxygen evolution reaction (OER) due to their easily tunable electronic, chemical, and physical properties. However, the poor electrical conductivity of metal-sulfide materials impedes their practical application in energy devices. Herein, firstly nano-sized crystals of cobalt-based zeolitic-imidazolate framework (Co-ZIF) arrays were fabricated on nickel-form (NF) as the sacrificial template by a facile solution method to enhance the electrical conductivity of the electrocatalyst. Then, the Co₃S₄/NiS@NF heterostructured arrays were synthesized by a simple hydrothermal route. The Co-ZIFs derived Co₃S₄ nanosheets are grown successfully on NiS nanorods during the hydrothermal sulfurization process. The bimetallic sulfide-based Co₃S₄/NiS@NF-12 electrocatalyst demonstrated a very low overpotential of 119 mV at 10 mA cm^?2 for OER, which is much lower than that of mono-metal sulfide NiS@NF (201 mV) and ruthenium-oxide (RuO₂) on NF (440 mV) electrocatalysts. Furthermore, the Co₃S₄/NiS@NF-12 electrocatalyst showed high stability during cyclic voltammetry and chronoamperometry measurements. This research work offers an effective strategy for fabricating high-performance non-precious OER electrocatalysts.     

Preparation of Culn(SxSe1−x)2 thin films by sulfurization and selenization

A CuIn(S_xSe_1−x)₂ alloy thin-film was prepared by selenization of CuInS₂: its composition ratio x can be controlled by the number of selenization cycles implemented. Crystallinity of the films was improved by annealing in vacuum. The resistivity of the film was about 1 Ω cm and increased by one to two orders of magnitude after KCN treatment. An 8.1 % efficiency solar cell was obtained by using this annealed alloy thin-film.     

Optical and photoelectrical properties of β-In2S3 thin films prepared by two-stage process

β-In₂S₃ films were grown on glass as well as on quartz substrates by rapid heating of metallic indium films in H₂S atmosphere. The effect of sulfurization temperature and time on the growth, structural, electrical and photoelectrical properties of β-In₂S₃ films has been investigated. Highly oriented single-phase β-In₂S₃ films were grown by the sulfurization technique. The morphology and composition of films have been characterized. The optical band gap of β-In₂S₃ is found to vary from 1.9 to 2.5 eV when the sulfurization temperature is varied from 300 to 600 °C or by increasing the sulfurization time. The electrical properties of the thin films have also been studied; they have n-type electrical conductivity. The photoelectrical properties of the β-In₂S₃ films are also found to depend on the sulfurizing temperature. A high photoresponse is obtained for films prepared at a sulfurizing temperature of 600 °C. β-In₂S₃ can be used as an alternative to toxic CdS as a window layer in photovoltaic technology.     

Preparation and properties of CuInS2 thin film prepared from electroplated precursor

Thin CuInS₂ films were prepared by sulfurization of Cu/In bi-layers. First, the precursor layer was electroplated onto the treated surface of Mo-coated glass. Observation of the cross-section prepared by focused ion beam (FIB) etching revealed that the void-free film was initially formed on the top surface of the precursor layer and continued to grow until the advancing front of the film reached the Mo layer. The nucleation of voids near the bottom of the CuInS₂ film followed. To determine whether the condition of the Cu/In alloy influences the CuInS₂ quality we investigated the Cu/In alloy state using FIB. We found that the annealed precursor of low Cu/In ratio (1.2) has several voids in the mid position in the layer compared with Cu-rich precursor (1.6). The cross-sectional view of the Cu-rich absorber layer is uniform compared with the low copper absorber layer. Thin film solar cells were fabricated using the CuInS₂ film (Cu/In ratio: 1.2) as an optical absorber layer. It was found that the optimization of a sulfurization period is important in order to improve the cell efficiency. We have not yet obtained good results with high Cu-rich absorber because of a blister problem. This blister was found before sulfurization. So, we are going to solve this blister problem before sulfurization.     

Electrical and optical properties of Cu2ZnSnS4 grown by a thermal co-evaporation method and its diode application

Cu₂ZnSnS₄ (CZTS) is low cost and constitutes non-toxic materials abundant in the earth crust. Environment friendly solar cell absorber layers were fabricated by a thermal co-evaporation technique. Elemental composition of the film was stated by energy dispersive spectroscopy (EDS). Some optical and electrical properties such as absorption of light, absorption coefficient, optical band gap charge carrier density, sheet resistance and mobility were extracted. Optical band gap was found to be as 1.44 eV, besides, charge carrier density, resistivity and mobility were found as 2.14×10¹⁹ cm⁻³, 8.41×10⁻⁴ Ω cm and 3.45×10² cm² V⁻¹ s⁻¹, respectively. In this study Ag/CZTS/n-Si Schottky diode was fabricated and basic diode parameters including barrier height, ideality factor, and series resistance were concluded using current–voltage and capacitance–voltage measurements. Barrier height and ideality factor values were found from the measurements as 0.81 eV and 4.76, respectively, for Ag/CZTS/n-Si contact.     

Effective surface roughening of three-dimensional copper foam via sulfurization treatment as a bifunctional electrocatalyst for water splitting

Cost effective electrocatalysts in water splitting reaction are critically important for the practical application of hydrogen fuel. The surface of three-dimensional copper foam is successfully roughened via one-step sulfurization reaction, and cuprous sulfide is formed on copper foam accordingly, which is denoted as Cu₂S@Cu. The as-prepared Cu₂S@Cu electrocatalyst exhibits remarkable performance on oxygen evolution reaction in basic solution, with a low overpotential of 345 mV to achieve 20 mA cm⁻². Cu₂S@Cu also shows enhanced performance on hydrogen production, compared to the original copper foam. Furthermore, Cu₂S@Cu can work as both cathode and anode in full water splitting, with superior activity to the noble metal-based electrocatalysts under large current densities. This study demonstrates that surface roughening technique on copper foam by sulfurization reaction can be valuable for developing novel copper-based electrocatalysts for water splitting.     

Co-Mo系耐硫变换催化剂硫化的探讨

介绍了耐硫变换催化剂的硫化原理及硫化工艺,阐述了硫化条件对耐硫变换催化剂活性的影响。     

长距离钢绳芯胶带输送机安装与调试

介绍晋宁磷矿长距离钢绳芯胶带输送机机架和驱动装置的安装、胶带接头钢丝绳的搭接方式、胶带接头强度保持率的试验、胶接硫化工艺及设备调试等。     

Formation of Cu3BiS3 thin films via sulfurization of Bi-Cu metal precursors

Thin films of Cu₃BiS₃ have been produced by conversion of stacked and co-electroplated Bi-Cu metal precursors in the presence of elemental sulfur vapor. The roles of sulfurization temperature and heating rate in achieving single-phase good quality layers have been explored. The potential loss of Bi during the treatments has been investigated, and no appreciable compositional difference was found between films sulfurized at 550 °C for up to 16 h. The structural, morphological and photoelectrochemical properties of the layers were investigated in order to evaluate the potentials of the compound for application in thin film photovoltaics.     

西藏某难处理氧化铜矿石浮选试验

西藏某铜矿石为高氧化率、嵌布粒度细、脉石矿物易泥化的难选氧化铜矿石,铜品位为1.76%,铜氧化率高达44.32%。根据矿石性质的特点,采用硫化铜矿物和氧化铜矿物分步浮选-混合精选流程进行了浮选试验。结果表明,矿石在磨矿细度为-0.074 mm占85%情况下,以水玻璃为矿泥的抑制剂和分散剂、戊基黄药为捕收剂、硫化钠为氧化铜矿物的硫化剂、硫酸铵为辅助活化剂、松醇油为起泡剂,通过2粗2精2扫流程处理,获得了铜品位为21.19%,铜回收率为78.74%的铜精矿。