Waste ceramic capacitors, which are widely present in e-waste and rich in BaTiO₃, Ag, Sn, Ni, and others, are valuable resources for recycling. Traditional pyrometallurgy and hydrometallurgy methods for separating metal elements from these capacitors are energy-intensive, involve lengthy processing steps, and generate waste liquids. This study breaks through the traditional idea of separating metal elements and proposes a one-step and efficient ball milling approach to directly transform the full compositions of waste ceramic capacitors into self-doped BaTiO₃ photocatalysts without the need for chemical reagents. The influences of ball-milling time and ball-to-waste ratio on the microstructural characteristics, optical properties, charge separation efficiency, and photocatalytic H₂ generation of the photocatalysts were investigated to reveal the mechanochemical effects and optimize the photocatalytic performance. The sample with a ball-to-waste ratio of 20:1 and ball-milling time of 1 h yielded small, uniform particles with high light absorption and charge separation, resulting in exceptional H₂ production of 191.3 μmol g^–1 h^–1. Our findings demonstrate the mechanochemical effects on the synthesis and optimization of self-doped BaTiO₃ photocatalysts from waste ceramic capacitors. This study also provides a strategy for directly recycling the full components of e-waste into functional materials without chemical consumption, thus avoiding the generation of waste liquids and achieving eco-friendly and high-value recycling of e-waste.

中文翻译：

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机械化学将废弃陶瓷电容器转化为自掺杂 BaTiO3 光催化剂：一种高价值电子垃圾回收和制氢的有效方法


废陶瓷电容器广泛存在于电子垃圾中，富含 BaTiO₃、Ag、Sn、Ni 等，是可回收利用的宝贵资源。从这些电容器中分离金属元素的传统火法冶金和湿法冶金方法需要大量能源，涉及漫长的加工步骤，并会产生废液。本研究突破了分离金属元素的传统思想，提出了一种一步高效的球磨方法，将废陶瓷电容器的全部成分直接转化为自掺杂的 BaTiO₃ 光催化剂，而无需化学试剂。研究了球磨时间和球废比对光催化剂微观结构特性、光学性质、电荷分离效率和光催化 H₂ 生成的影响，以揭示机械化学效应并优化光催化性能。球废比为 20：1、球磨时间为 1 h 的样品产生小而均匀的颗粒，具有高光吸收和电荷分离，从而产生 191.3 μmol g^–1 h^–1 的 H₂。我们的研究结果表明，机械化学对废陶瓷电容器自掺杂 BaTiO₃ 光催化剂的合成和优化有影响。本研究还提供了一种策略，可以将电子垃圾的全部成分直接回收成功能性材料，而无需消耗化学品，从而避免废液的产生，实现电子垃圾的环保和高价值回收。