Scholarlink

<p>Engineered biochar with enhanced photochemical properties holds great potential for environmental remediation. However, natural humic substances, crucial players in environmental redox processes, are structurally complex and slow-forming, hindering mechanistic insights and practical applications. Here, we propose a co-engineering strategy that combines biochar with artificial humic substances synthesized from pine sawdust via controlled hydrothermal humification (180–340&#xa0;°C). Modulating the hydrothermal temperature can yield artificial humic substances with diverse degradation degrees of lignin, yielding tailored phenolic architectures and electron-donating capacities (EDC). Using Ag⁺ photoreduction as a model reaction, we demonstrate that artificial humic substances produced at 340&#xa0;°C exhibit optimal phenol content and the strongest reducing capacity (19.2-fold greater than that of&#xa0;substances synthesized at 180 °C). Notably, higher molecular weight fractions (&gt; 5&#xa0;kDa) of artificial humic substances were found to dominate Ag⁺ photoreduction due to their enriched phenolic content and superior EDC. Mechanistic investigations reveal that photo-excited phenolic groups generate superoxide radical (O<sub>2</sub><sup>•−</sup>), initiating Ag⁺ reduction via a ligand-to-metal charge transfer (LMCT) pathway. Moreover, we discovered a previously overlooked phenomenon: hydrochar undergoes photo-induced dissolution, further enhancing photoreduction. This work provides new insights into the temperature-dependent lignin transformation into redox-active artificial humic substances and highlights the dynamic photochemical behavior of engineered biochar (hydrochar) under solar irradiation.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Co-engineering biochar and artificial humic substances: advancing photoreduction performance through structure design

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年1月15日

查看全文
  • Liming Sun,
  • Minghao Shen,
  • Chao Jia,
  • Fengbo Yu,
  • Shicheng Zhang,
  • Xiangdong Zhu

摘要

Engineered biochar with enhanced photochemical properties holds great potential for environmental remediation. However, natural humic substances, crucial players in environmental redox processes, are structurally complex and slow-forming, hindering mechanistic insights and practical applications. Here, we propose a co-engineering strategy that combines biochar with artificial humic substances synthesized from pine sawdust via controlled hydrothermal humification (180–340 °C). Modulating the hydrothermal temperature can yield artificial humic substances with diverse degradation degrees of lignin, yielding tailored phenolic architectures and electron-donating capacities (EDC). Using Ag⁺ photoreduction as a model reaction, we demonstrate that artificial humic substances produced at 340 °C exhibit optimal phenol content and the strongest reducing capacity (19.2-fold greater than that of substances synthesized at 180 °C). Notably, higher molecular weight fractions (> 5 kDa) of artificial humic substances were found to dominate Ag⁺ photoreduction due to their enriched phenolic content and superior EDC. Mechanistic investigations reveal that photo-excited phenolic groups generate superoxide radical (O2•−), initiating Ag⁺ reduction via a ligand-to-metal charge transfer (LMCT) pathway. Moreover, we discovered a previously overlooked phenomenon: hydrochar undergoes photo-induced dissolution, further enhancing photoreduction. This work provides new insights into the temperature-dependent lignin transformation into redox-active artificial humic substances and highlights the dynamic photochemical behavior of engineered biochar (hydrochar) under solar irradiation.

Graphical Abstract