Electrocatalytic hydrogen evolution reaction on sulfur-deficient MoS2 nanostructures

Molybdenum disulfide (MoS₂) is a 2D layered structured material with a Mo:S of 1:2 and is a great attention seeker for hydrogen production through water-splitting. In the present work, we prepared nanostructured MoS_x with different sulfur molar concentrations (x = 2, 1, 0.5) through a one-step hydrothermal method. The decrease in sulfur concentration resulted in a new phase that is MoO₃ with a Mo:S of 1:0.5. The structural, morphological, and optical properties of all the samples were studied through X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), and Ultraviolet–Visible (UV–Vis) spectroscopy, respectively. Moreover, the electrochemical behavior was studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and Tafel slope. Optimum properties were observed for Mo:S (1:1) with an onset potential of 96 mV, an overpotential of 130 mV for hydrogen evolution reaction (HER) coupled with a specific capacitance of 889 F/g and low charge transfer resistance of 43 Ω. Further, it was noted that the electrocatalytic activity of MoS₁ was better than that of the composite and bare MoO₃. It is proposed that the excellent electrochemical activity arises from sulfur vacancies which provide active sites for HER and a free path for ions to flow through the material.     

Optimization sulfur doping of electronic structure with metal active center for defect-rich FeCo bimetallic hydroxyl oxide catalysts

Defect engineering is an effective method to tune electronic states, which can provide active sites for electrocatalytic reactions. Herein, a highly efficient sulfur-doped bimetallic hydroxyl oxide (FeCo/Vc-S) has been synthesized by a two-step hydrothermal reaction, which has the rich defective and amorphous phases. The low coordination number of Co in X-ray absorption fine structure (XAFS) analysis further confirms the Co center is the active center, while Fe plays a role in optimizing the electronic structure of active Co species. Meanwhile, abundant oxygen vacancies and metal defects are also found in the material, which greatly enhances the adsorption and desorption efficiency of × OOH. Moreover, density functional theory (DFT) shows that the addition of S atom alters the electron distribution of adjacent metal atoms, thus adjusting the electron distribution of the metal active site. These positive factors endow FeCo/Vc-S with excellent OER electrocatalytic performance, with an overpotential of only 255 mV and Tafel slope is 64.3 mV·dec⁻¹ at a current density of 10 mA cm⁻². This study provides a new route for the synthesis of bimetallic hydroxyl oxides, and also provides theoretical design for the identification of active centers and defection-rich catalysts.     

杂多酸脱硫制硫新工艺

对几种不同种类和来源的杂多酸进行了实验筛选,对杂多酸溶液的氧化还原电位进行了实验测定。研究表明,杂多酸脱硫在热力学上是可行的,但实际过程中单一的杂多酸体系再生过程非常缓慢,难以实用;钒类化合物能够加速杂多酸的再生,两种钒类化合物对再生过程的催化性能相近。在实验条件下,ＨＰＡ分子中的Ｍｏ（Ⅵ）至少会转变为Ｍｏ（Ⅳ）,很大可能会转变为Ｍｏ（Ⅲ）。     

聚硫氯化铝和硫酸铝混凝剂使用效果的对比性研究

本文对新型净水剂——聚硫氯化铝和传统的硫酸铝混凝剂的净水效果进行对比研究。聚硫氯化铝在冬季低水温,高氨氮的原水情况下,不仅提高了出厂水水质,而且节省制水成本.并且简化了生产工艺的操作控制,值得推广。     

Synthesis and characterization of 1,2,3-selena/thiadiazoles linked to other heterocyclic units

Synthesis of novel 1,2,3-selena/thiadiazoles, linked to different benzo-1,3-heteroazole ring by sulfur has been reported. Structural features of the compounds have been analyzed by ¹H and ¹³C NMR, mass and single crystal X-ray studies.     

A novel study of sulfur-absorption via samarium-doped cerium sorbent at high temperature

Sulfides existing in many gas mixtures of high temperature cases have a negative effect on various industrial applications.In this study,we present samarium-doped cerium(SDC) sorbent to remove H2 S at high temperature.Compared with pure CeO_2,the SDC sorbent shows excellent ability in sulfur removal because of the positive effect of the doping of Sm.The H_2 has a negative influence on sulfidation of the SDC sorbent and significantly shortens the breakthrough time,hence breakthrough sulfur capacity(BSC).The carbon monoxide present in the feed gas has no obvious effect on the sulfur-removal performance,A suitable samarium loading in SDC leads to an optimum interaction between metal oxide species and the surface oxygen vacancies,which results in an optimal adsorbed activity of reduced gas(H_2,H_2 S) and hence desulphurization performance.In addition,the SDC sorbents have a good regenerated ability by a simple calcination process.     

大厂硫砷锡混合矿工艺矿物特性及硫砷分离试验研究

对大厂硫、砷、锡混合矿进行了工艺矿物特性及硫砷分离试验研究 ,实现了硫、砷分离     

云南某高硫铁矿石深度降硫试验研究

云南某高硫铁矿石因含磁黄铁矿而造成精矿含硫超标。为此，对该矿石进行了旨在降低精矿中硫含量的选矿试验。试验采用弱磁选-浮选工艺流程，通过组合活化剂NC和新型捕收剂DY对磁黄铁矿的有效作用，最终使精矿中的硫降至0.08%，并使精矿铁品位达到65.04%。     

某复杂难选铜铅锌多金属硫化矿选矿试验

辽宁葫芦岛地区某金、银品位较高的铜铅锌多金属硫化矿石结构构造复杂,铜、铅、锌分离难度较大。为高效开发利用该矿石,按优先混浮铜铅-混浮精矿铜铅分离-混浮尾矿抑硫浮锌的原则流程对该矿石进行了系统的选矿试验。结果表明,采用2粗1扫2精铜铅混浮、1粗2扫3精铜铅分离、1粗2扫2精选锌、中矿顺序返回的闭路流程处理该矿石,最终获得了铜、金、银品位分别为20.88%、2.37 g/t、1 808 g/t,铜、金、银回收率分别为85.72%、46.27%、22.46%的铜精矿,铅、金、银品位分别为63.13%、0.99 g/t、5 973 g/t,铅、金、银回收率分别为80.00%、19.57%、75.16%的铅精矿,锌、金、银品位分别为55.96%、0.35 g/t、37.80 g/t,锌、金、银回收率分别为84.21%、10.47%、0.72%的锌精矿,较好地实现了铜、铅、锌的分离回收。     

西南地区硫磺市场与定价机制分析

在分析我国硫磺产销及进口情况、西南地区硫磺市场供需状况及竞争趋势的基础上,研究了川东北地区硫磺目标市场和定价机制。认为川东北周边地区硫磺销售市场前号较好,但同时与进口硫磺存在激烈的市场竞争,建议川东北硫磺销售企业采取更科学的销售模式、更合理的销售办法和更灵活的销售手段,同时采取市场定价的方法。