Ramaswamy Kadari, Radha Velchuri, Malathi M, Vithal Muga, Munirathnam Nagegownivari R
Centre for Materials for Electronics Technology (CMET), Cherlapally, HCl (PO), Hyderabad 500051, India.
Department of Chemistry, Osmania University, Hyderabad 500 007, India.
Waste Manag. 2017 Feb;60:629-635. doi: 10.1016/j.wasman.2016.09.026. Epub 2016 Oct 4.
The disposal and reuse of waste printed circuit boards have been the major global concerns. Printed circuit boards, a form of Electronic waste (hereafter e-waste), have been chemically processed, doped with Ag, Cu and Sn, and used as visible light photocatalysts against the degradation of methylene blue and methyl violet. The elemental analyses of pristine and metal doped printed circuit board were obtained using energy dispersive X-ray fluorescence (EDXRF) spectra and inductively coupled plasma optical emission spectroscopy (ICP-OES). The morphology of parent and doped printed circuit board was obtained from scanning electron microscopy (SEM) measurements. The photocatalytic activity of parent and metal doped samples was carried out for the decomposition of organic pollutants, methylene blue and methyl violet, under visible light irradiation. Metal doped waste printed circuit boards (WPCBs) have shown higher photocatalytic activity against the degradation of methyl violet and methylene blue under visible light irradiation. Scavenger experiments were performed to identify the reactive intermediates responsible for the degradation of methylene blue and methyl violet. The reactive species responsible for the degradation of MV and MB were found to be holes and hydroxyl radicals. A possible mechanism of degradation of methylene blue and methyl violet is given. The stability and reusability of the catalysts are also investigated.
废弃印刷电路板的处置与再利用一直是全球主要关注的问题。印刷电路板作为电子废弃物（以下简称电子垃圾）的一种形式，已进行化学处理，掺杂银、铜和锡，并用作可见光光催化剂以对抗亚甲基蓝和甲基紫的降解。使用能量色散X射线荧光光谱法（EDXRF）和电感耦合等离子体发射光谱法（ICP - OES）对原始及金属掺杂的印刷电路板进行元素分析。通过扫描电子显微镜（SEM）测量获得原始及掺杂印刷电路板的形态。在可见光照射下，对原始及金属掺杂样品的光催化活性进行了有机污染物亚甲基蓝和甲基紫分解的测试。金属掺杂的废弃印刷电路板（WPCBs）在可见光照射下对甲基紫和亚甲基蓝的降解表现出更高的光催化活性。进行了清除剂实验以确定负责亚甲基蓝和甲基紫降解的反应中间体。发现负责甲基紫（MV）和亚甲基蓝（MB）降解的反应物种为空穴和羟基自由基。给出了亚甲基蓝和甲基紫降解的可能机制。还研究了催化剂的稳定性和可重复使用性。
