Hossain Md Sahadat, Tuntun Supanna Malek, Bahadur Newaz Mohammed, Ahmed Samina
Glass Research Division, Institute of Glass & Ceramic Research and Testing, Bangladesh Council of Scientific and Industrial Research (BCSIR) Dhaka 1205 Bangladesh.
Department of Applied Chemistry and Chemical Engineering, Noakhali Science and Technology University Noakhali Bangladesh.
RSC Adv. 2022 Nov 28;12(52):34080-34094. doi: 10.1039/d2ra06294a. eCollection 2022 Nov 22.
This research deals with the photocatalytic activity of hydroxyapatite and the improvement of efficiency by doping various percentages of copper; the catalysts were synthesized by the wet-chemical method. Pure and copper-doped photocatalysts were characterized by several techniques including X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), dynamic scanning calorimetry (DSC), and UV-Vis spectroscopy. The competency of pure and copper-doped hydroxyapatite as photocatalysts was assessed by their interaction with Congo red dye. The crystallographic parameters of the catalysts were also estimated by employing the XRD technique, and a relationship was established between the calculated parameters and photocatalytic performance. Crystallite size was calculated from various model equations, which revealed an acceptable crystallite size of 42-68 nm. Copper doping in hydroxyapatite impressively augmented the photocatalytic efficacy, for example 99% dye was degraded upon 0.63% Cu-doping compared to 75% for the pure HAp, which was exemplified not only by the reaction rate but also by the quantum yield. The degradation percentages changed with time but became fixed at 200 min. The molar extinction coefficient was estimated by employing the Beer-Lambert law and further utilized to compute the photonic efficiency of the catalysts. In the study of the photochemical reaction, a simplified reaction process was proposed, and the potentials of the conduction band and valence band were assessed, which influenced the activity. The doping of Cu in crystalline hydroxyapatite will enhance the photocatalytic activity towards Congo red dye under all experimental conditions.
本研究涉及羟基磷灰石的光催化活性以及通过掺杂不同百分比的铜来提高效率；催化剂采用湿化学法合成。通过多种技术对纯的和铜掺杂的光催化剂进行了表征，包括X射线衍射（XRD）、傅里叶变换红外（FTIR）光谱、拉曼光谱、扫描电子显微镜（SEM）、热重分析（TGA）、动态扫描量热法（DSC）以及紫外可见光谱。通过纯的和铜掺杂的羟基磷灰石与刚果红染料的相互作用来评估它们作为光催化剂的能力。还采用XRD技术估算了催化剂的晶体学参数，并在计算得到的参数与光催化性能之间建立了关系。通过各种模型方程计算出微晶尺寸，结果显示微晶尺寸在42 - 68 nm之间，是可接受的。在羟基磷灰石中掺杂铜显著提高了光催化效率，例如，与纯HAp的75%相比，0.63%的铜掺杂使染料降解率达到99%，这不仅体现在反应速率上，也体现在量子产率上。降解百分比随时间变化，但在200分钟时趋于稳定。利用比尔 - 朗伯定律估算了摩尔消光系数，并进一步用于计算催化剂的光子效率。在光化学反应研究中，提出了一个简化的反应过程，并评估了导带和价带的电位，这些电位影响了活性。在所有实验条件下，在结晶羟基磷灰石中掺杂铜都会增强对刚果红染料的光催化活性。
