Characterization and quantification of electron donating capacity and its structure dependence in biochar derived from three waste biomasses
Characterization and quantification of electron donating capacity and its structure dependence in biochar derived from three waste biomasses
复制标题
三种废弃生物质生物炭的供电子能力及其结构依赖性的表征和定量
DOI：
10.1016/j.chemosphere.2018.08.033
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发表时间：
2018
期刊：
影响因子：
8.8
通讯作者：
Cao Xinde
中科院分区：
文献类型：
--
作者：
Zhang Yue;Xu Xiaoyun;Cao Lingzhi;Ok Yong Sik;Cao Xinde
生物炭具有独特的电化学性质，参与了土壤和水中的各种氧化还原反应。用介电氧化方法研究了松材、麦草和麦草在2 0 0~80 0 °C范围内热解生物炭的给电子能力。所有生物炭的EDC值在0.18~1.83 −(G Biochar)−1范围内，表现为随着温度的升高而增加，从400 °C升高到400 °C，从400 °C下降到650 °C，然后从650 °C增加到800 °C。在200-650 °C的中低温度下，EDC值主要由酚羟基组成。而与芳香族结构有关的共轭π电子体系在650 °C以上的高温下占主导地位，麦草和麦草生物质炭的生物质生物质碳的生物质生物质炭具有较高的生物质生物质炭的生物质碳具有较高的生物质能谱，这是由于前者的酚羟基含量高于后者。综上所述，生物炭的还原性能主要归因于酚羟基和与芳香族结构有关的共轭π-电子体系，这取决于热解温度和原料来源。这些结果将有助于我们全面了解生物炭在生物地球化学氧化还原反应中的作用，并考虑开发具有受控氧化还原性能的生物炭，用于特定的环境应用，如电子穿梭和催化剂材料。
Biochar has shown a unique electrochemical property being involved in various redox reactions in soil and water. In this study, the electron donating capacities (EDCs) of biochar pyrolyzed at 200–800 °C from pine wood, barley grass and wheat straw were investigated by using the mediated electrochemical oxidation method. The EDC values for all biochar were in the range of 0.18–1.83 mmol e−(g biochar)−1, showing the increase as the temperature increased from 200 °C to 400 °C, the decrease from 400 °C to 650 °C, and then increase from 650 °C until to 800 °C. At low and intermediate temperatures of 200–650 °C, the EDCs were mainly attributed to the phenolic hydroxyl groups, while the conjugated π-electron system associated with aromatic structure dominated the EDCs of biochar at the high temperatures of over 650 °C. The barley grass- and wheat straw-derived biochar had higher EDCs than the pine wood-derived biochar, resulting from the higher phenolic hydroxyl groups in the former samples than the latter one. In conclusion, the reductive property of biochar was mainly attributed to both phenolic hydroxy group and conjugated π-electron system associated with aromatic structure, depending on the pyrolytic temperature and feedstock source. The results will help us to obtain a complete view on the role of biochar in biogeochemical redox reactions and consider developing biochar with controlled redox properties for specific environmental applications such as electron shuttle and catalyst material.