Solvothermal syntheses of Cu3P via reactions of amorphous red phosphorus with a variety of copper sources

Polycrystalline Cu₃P was successfully prepared under a wide variety of solvothermal conditions. The reaction of red phosphorus with several copper sources (copper metal, copper (I) iodide, copper (I) chloride and copper (II) chloride) at 150-200 °C for 1-2 days in water produced Cu₃P. Products were examined with powder X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Thermal analyses and optical spectroscopy were also performed. A detailed list of reaction conditions, products and impurity phases (where applicable) are reported.     

New Route of Microwave-Assisted Synthesis of Carbon-Supported Nickel Phosphide (C/Ni2P) Nanocomposite

Abstract

A novel, fast, and easy method for synthesizing a carbon-supported Ni₂P nanocomposite (C/Ni₂P) is described. The process involves a reaction between a nickel salt, phosphoric acid, and a carbon source by utilizing microwave irradiation. The carbon source for the nanocomposite is from renewable supplies, namely, tannin and lignin. The method has successfully synthesized Ni₂P nanoparticles dispersed in a carbon matrix with a particle size ranging from 20 to 50 nm in diameter. During the microwave process, tannin and lignin provided a reducing environment in the microwave irradiation process. The synthesized products are characterized by several characterization methods. The method showed that phosphoric acid, which is a nontoxic compound, could be used as an alternative P source for synthesizing Ni₂P. The method is fast, easy, and an economical process to synthesize the carbon-coated Ni₂P nanocomposite.     

A Further Extension of Pnictide Oxide Chemistry – Synthesis and Structure of La2AuP2O

The phosphide oxide La₂AuP₂O was synthesized from lanthanum filings, dried La₂O₃, gold pieces, and ground red phosphorus in the ideal 1.33:0.33:1:2 ratio in an evacuated silica tube at 1473 K. Small single crystals were obtained by recrystallization in a NaCl/KCl flux. The structure was determined on the basis of single‐crystal X‐ray diffractometer data: new type, C2/m, a = 1537.3(3), b = 427.39(8), c = 1009.2(2) pm, β = 131.02(1) °, wR₂ = 0.046, 1102 F² values, 38 variables. La₂AuP₂O contains two striking structural motifs: The oxygen atoms are located in La₄ tetrahedra. The latter are cis‐edge‐shared forming polymeric cationic [La₂O]⁴⁺ chains. These cationic units are separated and charge‐balanced by [AuP₂]^4– polyanions which have monovalent gold in distorted trigonal planar phosphorus coordination. Two crystallographically independent phosphorus sites occur in the polyanion, i.e. isolated P^3– besides dumb‐bells P₂^4– (P2–P2 223 pm). La₂AuP₂O, which crystallizes in the form of ruby red transparent crystals, is an electron precise phosphide oxide (4La³⁺)(2Au⁺)(2P^3–)(P₂^4–)(2O^2–).     

结晶紫在纳米磷化镓粉体表面吸附的表面增强拉曼光谱分析

利用Raman光谱对结晶紫(Crystal Violet,CV)在纳米磷化镓(GaP)粉体表面的吸附状态进行了分析.结果表明:与普通拉曼散射谱(Normal Raman Scattering,NRS)相比,结晶紫表面增强拉曼散射(Surface Enhanced Raman Scattering,SERS)谱的4种振动模式,即:中央键的呼吸振动、环-C -环面外弯曲振动、环C-H面外弯曲振动以及N-环伸缩振动,在纳米GaP粉体表面得到增强;通过分析吸附前后结晶紫拉曼散射峰相对强度的变化,确定了结晶紫在纳米GaP粉体表面的吸附取向,并对其表面增强散射机理进行了探讨.     

Breaking Surface Atomic Monogeneity of Rh2P Nanocatalysts by Defect-Derived Phosphorus Vacancies for Efficient Alkaline Hydrogen Oxidation

Breaking atomic monogeneity of catalyst surfaces is promising for constructing synergistic active centers to cope with complex multi-step catalytic reactions. Here, we report a defect-derived strategy for creating surface phosphorous vacancies (P-vacancies) on nanometric Rh₂P electrocatalysts toward drastically boosted electrocatalysis for alkaline hydrogen oxidation reaction (HOR). This strategy disrupts the monogeneity and atomic regularity of the thermodynamically stable P-terminated surfaces. Density functional theory calculations initially verify that the competitive adsorption behavior of H_ad and OH_ad on perfect P-terminated Rh₂P{200} facets (p-Rh₂P) can be bypassed on defective Rh₂P{200} surfaces (d-Rh₂P). The P-vacancies enable the exposure of sub-surface Rh atoms to act as exclusive H adsorption sites. Therein, the H_ad cooperates with the OH_ad on the peripheral P-sites to effectively accelerate the alkaline HOR. Defective Rh₂P nanowires (d-Rh₂P NWs) and perfect Rh₂P nanocubes (p-Rh₂P NCs) are then elaborately synthesized to experimentally represent the d-Rh₂P and p-Rh₂P catalytic surfaces. As expected, the P-vacancy-enriched d-Rh₂P NWs catalyst exhibits extremely high catalytic activity and outstanding CO tolerance for alkaline HOR electrocatalysis, attaining 5.7 and 14.3 times mass activity that of p-Rh₂P NCs and commercial Pt/C, respectively. This work sheds light on breaking the surface atomic monogeneity for the development of efficient heterogeneous catalysts.     

The stability and surface reactivity of gallium phosphide nanocrystals

The stability and surface reactivity of Gal? nanocrystals were characterized by TG-DTA, XRD and XPS measurements. The samples were heated in O₂ and N₂ atmospheres respectively. The experimental curve which describes the mass change as a function of temperature shows that the mass decreases under 330°C but increases in two stages between 33°C and 550°C. The curves obtained in O₂ and N₂ are obviously different. The results of XPS indicate that the density of oxygen atoms bonded chemically to the gallium atoms on the surface increases when the sample is heated in O₂ up to 200°C, whereas the density of nitrogen atoms increased when heated to 330°C in N₂. It can be concluded that the N₂ could be activated on the surface of GaP nanocrystals at a rather low temperature, and highly reactive nitrogen atoms formed. Our result obtained makes it possible to synthesize a series of nitrogen-containing compounds in N₂ gas under moderate conditions.     

大规模合成非贵金属磷化物/CdS复合光催化剂高效可见光催化产氢（英文）

目前,在可见光照射下光催化产氢是一条解决能源短缺的理想途径.该途径实现工业化的两个关键因素是得到低成本的光催化剂和高的产氢效率.非贵金属助催化剂代替贵金属可大大降低光催化剂的成本.通过简单的方法大规模合成并组装半导体和非贵金属助催化剂以形成复合光催化剂可进一步降低成本.本文采用大规模和低成本的共沉淀法合成了磷化物/CdS光催化剂,实现了光催化产氢.当负载CoP和Mo P助催化剂后,光催化产氢活性得到大幅度提高.其中CoP/CdS和Mo P/CdS的最佳产氢量分别为140和78μmol/h,并分别为CdS的7.0倍和4.0倍,分别为Pt/CdS的2.0倍和1.1倍.这说明磷化物CoP和Mo P是具有优良催化活性的低成本非贵金属助催化剂,可以代替贵金属助催化剂应用在光催化产H_2中.在制备磷化物/CdS时,先将两种磷化物反应原料分别在水热反应釜和马弗炉中煅烧合成前驱体,再分别在管式炉氮气和氢气氛围中进行磷化得到磷化物Mo P和CoP.然后,将得到的Mo P和CoP分别溶解在Cd(NO_3)_2·4H_2O溶液中,在搅拌状态下逐滴加入Na_2S溶液形成沉淀,即可得到复合物磷化物/CdS.CoP/CdS和Mo P/CdS的HRTEM观察显示,磷化物助催化剂与CdS半导体紧密结合,证明了共沉淀法制备助催化剂/半导体复合光催化剂的有效性.磷化物与CdS的紧密结合促进了光激发电子从CdS向磷化物转移,从而大大提高了光催化产氢活性.这项工作为低成本大规模制备光催化剂和光催化产H_2实现工业化提供了一条可行性思路.