Developing highly efficient, stable, and full-spectrum responsive non-precious photocatalyst is high desirable due to photocatalytic water splitting is a green technology for hydrogen evolution. In this work, a type of biochar-based composite photocatalysts is fabricated by a facile green microwave-assisted aqueous chemical deposition, which consists of monodispersed Zn_0.2Cd_0.8S nanoparticles (ZCS NPs) uniformly decorating on three-dimensional (3D) biochar aerogel (BA) derived from the biomass castoff tangerine peel. As-engineered ZCS/BA composite photocatalysts exhibit significantly strengthened photocatalytic activities under solar irradiation, in which the optimal 0.4ZCS/BA sample (0.4 represents the molar of ZCS) achieves the average photocatalytic hydrogen production efficiency of 10.52 mmol g⁻¹∙h⁻¹, being 24.5 folds higher than that of monolithic ZCS alloy. The boosted photocatalytic hydrogen evolution is ascribed to the synergistic effect on the heteroarchitecture with the closely interfacial interaction, which is beneficial for increasing the broad-spectrum sunlight absorption, promoting the photo-induced charge carriers separation efficiency, and accelerating the chemical reaction dynamic rate by the photothermal effect. The step-scheme (S-scheme) electron transfer mechanism for binary ZCS/BA heterojunction is proposed based on the experimental data and density functional theory (DFT) calculation. The study guides a practical approach to developing biochar-based composites for highly efficient utilization of agricultural biomass resources as well as conversion of solar energy to fuel in photocatalysis.

由于光催化水分解是一种绿色的析氢技术，因此开发高效、稳定和全光谱响应的非贵金属光催化剂是非常可取的。在这项工作中，一种基于生物炭的复合光催化剂是通过一种简便的绿色微波辅助水相化学沉积法制备的，它由单分散的 Zn _0.2 Cd _0.8组成S 纳米粒子 (ZCS NPs) 均匀地装饰在源自生物质废弃陈皮的三维 (3D) 生物炭气凝胶 (BA) 上。设计后的 ZCS/BA 复合光催化剂在太阳辐射下表现出显着增强的光催化活性，其中最佳 0.4ZCS/BA 样品（0.4 代表 ZCS 的摩尔数）实现了 10.52 mmol g −1 ∙h − 的平均光催化^制氢效率^{。 1个}，比单片 ZCS 合金高 24.5 倍。促进的光催化析氢归因于具有紧密界面相互作用的异质结构的协同效应，有利于增加广谱太阳光吸收，提高光诱导电荷载流子分离效率，加快化学反应动态速率。光热效应。基于实验数据和密度泛函理论（DFT）计算，提出了二元ZCS/BA异质结的阶梯式（S-scheme）电子转移机制。该研究指导了开发基于生物炭的复合材料的实用方法，以高效利用农业生物质资源以及在光催化中将太阳能转化为燃料。