磷化法制备Ni x P y 及其复合材料光解水性能

磷化镍具有Ni₃P、Ni₁₂P₅、Ni₂P、Ni₅P₄等多种晶相，深入研究各个晶相的制备规律和稳定存在条件对开发磷化镍基催化材料至关重要。本文系统考察了磷化时间、磷化温度、Ni/P摩尔比、磷化气速和磷源种类对制备晶相的影响。结果发现，以Ni₃P为前体、红磷为磷源时，可以得到Ni₅P₄、Ni₂P、Ni₁₂P₅三种晶相；以次磷酸盐为磷源时只能得到Ni₂P和Ni₁₂P₅晶相。当以红磷为磷源时，反应温度是影响晶相的主要因素，磷化温度为500℃、600℃和800℃时分别得到Ni₅P₄、Ni₂P和Ni₁₂P₅晶相。将制备的Ni₃P、Ni₂P、Ni₁₂P₅和Ni₅P₄作为助剂，与CdS复合制备光催化复合材料，得到的4种Ni _x P _y /CdS复合材料均表现出良好的光解水制氢性能，Ni₅P₄/CdS表现出最优的产氢能力，为CdS的5.4倍。表征结果证明，引入Ni _x P _y 能够有效抑制反应过程中CdS的载流子复合，提升其光解水反应活性。

Photocatalytic properties of NixPy and its composites prepared by phosphating method

Nickel phosphide (Ni _x P _y ) has many crystalline phases, such as Ni₃P, Ni₁₂P₅, Ni₂P, Ni₅P₄, etc. It is important to study the preparation rule and stable existence conditions of each crystalline phase for the development of catalysts based on Ni _x P _y . In this paper, the effects of phosphating time, phosphating temperature, Ni/P molar ratio, phosphating gas velocity and phosphorus source on the crystal phase were investigated. The results showed that three crystalline phases of Ni₅P₄, Ni₂P and Ni₁₂P₅ can be obtained with Ni₃P and red phosphorus as precursors. Only Ni₂P and Ni₁₂P₅ crystal phases can be obtained with hypophosphite as phosphorus source. The reaction temperature was the main factor affecting the crystal phase when red phosphorus was used as the phosphorus source. Ni₅P₄, Ni₂P and Ni₁₂P₅ crystal phases were obtained at 500℃, 600℃ and 800℃, respectively. Ni₃P, Ni₂P, Ni₁₂P₅ and Ni₅P₄ were used as cocatalysts to prepare photocatalytic composites. All the four cocatalysts of Ni _x P _y can significantly enhance the hydrogen production activity of CdS. Ni₅P₄/CdS indicated the best hydrogen production capacity, which was 5.4 times that of CdS. The results of characterization showed that the introduction of Ni _x P _y could effectively inhibit the carrier recombination and enhance the photocatalytic activity of CdS.