材料期刊网

用电化学方法研究了碱性溶液中硫化物在Pt电极上的氧化过程。结果表明，硫离子在-600～+750mV(vs.SCE)存在两个电化学氧化过程。经热力学、动力学和化学分析证实，在约-400mV时硫离子首先氧化为单质硫及多硫化物，沉积在电极表面；约250 mV处，单质硫及多硫化物进一步氧化为硫酸根离子而进入溶液。低电位下的氧化反应是可逆反应，硫离子扩散为控制步骤；高电位下，单质硫进一步氧化为硫酸根离子的反应是不可逆反应。而两反应过程密切相关。

Electrochemical oxidization of sulfide on platinum in alkaline solution has been studied by using electrochemical techniques.Results indicate that the two oxidizations of sulfide exist in the range from － 600 mV to ＋ 750 mV(vs.SCE).From the point of view of thermodynamics,chemical analysis and kinetics,at － 400 mV the sulfide is first oxidized to sulphur and polysulfides deposited on the electrode,and at 250 mV sulphur is further oxidized to sulfate entering solution.Oxidization under lower potential is a reversible reaction and the rate-determining step of this reaction is sulfide ions-diffusion controlling.The reaction that sulphur is further oxidized to sulfate under higher potential is an irreversible reaction.These two processes are closely correlated with each other.