The recovery of scattered metal ions such as perrhenate (Re(VII)) from industrial effluents has enormous economic benefits and promotes resource reuse. Nanoscale-metal/biochar hybrid biosorbents are attractive for recovery but are limited by their insufficient stability and low selectivity in harsh environments. Herein, a superstable biochar-based biosorbent composed of ZnO nanoparticles with remarkable superhydrophobic features is fabricated, and its adsorption/desorption capabilities toward Re(VII) in strongly acidic aqueous solutions are investigated. The ZnO nanoparticle/biochar hybrid composite (ZBC) exhibits strong acid resistance and high chemical stability, which are attributable to strong C-O-Zn interactions between the biochar and ZnO nanoparticles. Due to the advantages of its hydrolytic stability, superhydrophobicity, and abundance of Zn-O sites, the ZBC proves suitable for the effective and selective separation of Re(VII) from single, binary and multiple ion systems (pH = 1), with a maximum sorption capacity of 29.41 mg/g. More importantly, this material also shows good recyclability and reusability, with high adsorption efficiency after six adsorption-desorption cycles. The findings in this work demonstrate that a metal/biochar hybrid composite is a promising sorbent for Re(VII) separation.

从工业废水中回收高铼酸 (Re(VII)) 等分散的金属离子具有巨大的经济效益，促进了资源的再利用。纳米级金属/生物炭混合生物吸附剂对回收很有吸引力，但在恶劣环境中稳定性不足和选择性低而受到限制。在此，制备了一种由具有显着超疏水特性的 ZnO 纳米颗粒组成的超稳定生物炭基生物吸附剂，并研究了其在强酸性水溶液中对 Re(VII) 的吸附/解吸能力。ZnO 纳米颗粒/生物炭杂化复合材料 (ZBC) 表现出很强的耐酸性和高化学稳定性，这归因于生物炭和 ZnO 纳米颗粒之间强烈的 CO-Zn 相互作用。由于其水解稳定性、超疏水性、和丰富的 Zn-O 位点，ZBC 证明适用于从单离子、二元和多离子系统（pH = 1）中有效和选择性地分离 Re(VII)，最大吸附容量为 29.41 mg/g。更重要的是，该材料还表现出良好的可回收性和重复使用性，经过六次吸附-解吸循环后具有较高的吸附效率。这项工作的发现表明，金属/生物炭杂化复合材料是一种很有前途的 Re(VII) 分离吸附剂。