热解温度对生物炭循环伏安曲线特性的影响

随着生物炭在农业和环境领域的应用逐渐增多,生物炭对环境中生物化学过程的影响也日益加深.本文利用循环伏安曲线,探究了不同热解温度下生物炭的电子传递方式.结果发现,在热解温度为400℃时,生物炭的电导率较低,而循环伏安曲线上存在明显的氧化还原峰,这表明生物炭的电子传递方式以官能团的氧化还原反应过程为主.随着热解温度升高,以含氧官能团为主的氧化还原活性物质含量降低,氧化还原峰的峰电流降低;同时,生物炭比表面积增大、导电性增强,循环伏安曲线形状逐渐变为梭形,响应电流也逐渐增大;这表明生物炭的电子传递方式逐渐转变为主要依靠生物炭导电性的方式.总之,循环伏安曲线可以定性地分析生物炭的电子传递方式,为探究生物炭不同电子传递方式对生物化学过程的影响提供了一定的研究基础.

Effect of carbonization temperature on the cycle voltammetry characteristics of biochar

With the increasing application of biochar in agriculture and environment fields,the influence of biochar on the biochemical processes in the environment increased.In this study,we used cyclic voltammetry curves to explore the electron transfer properties of biochar at different pyrolysis temperatures.The experimental results showed that,when the pyrolysis temperature was 400℃,there were obvious redox peaks on the cyclic voltammetry curve of biochar with low conductivity;the existence of redox peaks indicated that the electron transfer mode of biochar was mainly the redox reaction process of functional groups.As the pyrolysis temperature increased,the redox-active substances mainly containing oxygen-containing functional groups decreased,and the redox peak currents decreased,and both the specific surface area and the conductivity increased.The shape of the cyclic voltammetry curve became fusiform with higher response current,indicating that the electron transfer mode of biochar changed to a mode mainly depended on biochar conductivity.In summary,the study showed that the cyclic voltammetry curve could analyze the electron transfer mode of biochar qualitatively,which provided support to explore the influence of different electron transfer modes on the biochemical process of biochar.