半导体矿物材料添加及光催化对海南红壤稻田土壤呼吸的影响

Paddy Soil Respiration Induced by Semiconductor Minerals addition and photocatalysis in the Red Soil Region of South China

南方红壤中存在大量的半导体矿物,这些半导体矿物在光照条件下可产生光电子-空穴对,对土壤地球化学循环具有重要影响。我们推断土壤中的半导体矿物光催化可影响土壤呼吸。为了分析半导体矿物催化对土壤呼吸变化的影响,以及半导体矿物光生电子的作用方式,从而加深对南方稻田土壤呼吸的深入了解,本研究以海南英州镇水稻土为研究对象,选择半导体矿物Ti O2以及空穴捕获剂(溴化钠)作为处理,在相同温度(28℃)条件下,设置有光(3000 lux)和无光对照,研究半导体矿物光催化对土壤呼吸的影响。结果显示,光照增加了南方水稻土土壤呼吸。加入一定浓度半导体矿物Ti O2后土壤呼吸释放CO2的量增加,而在加入空穴捕获剂后土壤呼吸释放CO2的量减少。由此可见,半导体矿物Ti O2在光催化作用下所产生的具有氧化还原能力的电子-空穴对激发了南方红壤区稻田的土壤呼吸。

Red Soil in southern China contains a large number of semiconductor minerals,which produce photoelectron-hole pairs under light conditions and have important effects on soil geochemical cycles.We hypothesized that photocatalysis of semiconductor minerals in soil can affect soil respiration.We analyzed the effect of semiconductor mineral catalysis on soil respiration and the action mode of photogenerated electrons of semiconductor minerals,so as to deeply understand paddy soil respiration in southern China.In this study,semiconductor mineral Ti O2 and hole trapping agent(sodium bromide)were selected as treatment objects,and light(3000 lux)and no light control were set up at the same temperature(28℃)to study the effect of semiconductor mineral photocatalysis on soil respiration.The results showed that the illumination increased the paddy soil respiration.The amount of CO2 released by soil respiration was increased after the addition of a certain concentration of semiconductor mineral Ti O2,but was decreased after the addition of hole-trapping agent.It can be seen that the electron-hole pair with redox ability produced by semiconductor mineral Ti O2 under the action of photocatalysis stimulates paddy soil respiration in the Red Soil area of southern China.