鈷摻雜二硫化鐵/磷化鐵複合材料的合成與其作為析氫觸媒之應用

Abstract

在全球人口快速成長與能量消耗情況下，再生能源的需求逐漸受到關注。在眾多替代能源中，電解水產氫 (water electrolysis) 被視為最具發展潛力之一，因其方法簡單、產生氫氣濃度高且過程中不會產生危害地球的溫室氣體，例如二氧化碳及甲烷等。在析氫反應中，鉑金屬之類的貴金屬研究出具有高效能的催化活性，但其價格昂貴且含量少，受到許多限制。因此開發出新穎、便宜且地表含量豐富的析氫觸媒成為我們重要的研究方向。

本研究中，我們以化學氣相沉積法合成出鈷摻雜二硫化鐵/磷化鐵複合材料，由硫與磷產生之異質結構並提高整體比表面積，而露出更多活化位置，藉此特性可有效提升其在析氫觸媒上的表現。

鈷摻雜二硫化鐵/磷化鐵比起一些文獻報導的純硫化物、純磷化物和非貴金屬在酸性環境下中具有更好的析氫活性效率。在極化曲線量測中發現，其異質結構之 Onset potential 約 30 mV ，Tafel slope 值計算約 41.5 mV/dec ;對於電流與時間相對關係下持續的測量一個星期，鈷摻雜二硫化鐵/磷化鐵仍維持其初始電流量，展現其高穩定度。

In condition of rapid growth global population and energy consumption, the issues have triggered the urgent demand for renewable and clean energy sources.

Water electrolysis has been considered as one of the most potential for alternative energy in the future. It has many advantages, such as easy in use, high efficiency, high purity in producing hydrogen, , etc., during the process of releasing energy, hydrogen is not produce green-house-effect gas, such as CO2 or CH4.

In the numerous of noble metals, platinum has been reported as high efficiency in the hydrogen evolution reaction (HER), whereas its high cost and low abundance hinder the large-scale application. Thus, research on designing new, inexpensive, and abundant catalyst in hydrogen evolution reaction is our goal.

In this work , we synthesis heterostructure cobalt-doped iron sulfide/iron phosphide with chemical vapor deposition method where synergistic effects between sulfur and phosphorus produce a high-surface-area and exposes a large fraction of edge sites, leads to excellent activity for hydrogen evolution.

The heterostructure cobalt-doped iron sulfide/iron phosphide exhibited superior electrocatalytic activity in the hydrogen evolution reaction (HER) rather than those based on either the pure sulfide or the pure phosphide in acidic environments. The heterostructure showed an overvoltage requirement only 30 mV. A Tafel slope of ~41.5 mV/decade was calculated. The catalyst exhibits remaining perfectly stable in accelerated durability testing for a week.