Department of Chemistry, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India.
Department of Chemical Engineering, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India.
Environ Sci Pollut Res Int. 2022 Aug;29(37):56684-56695. doi: 10.1007/s11356-022-19808-5. Epub 2022 Mar 26.
Sunlight active blue emissive zirconium, nitrogen, and sulfur co-doped carbon dots (Zr-N-S-CDs) have been synthesized by microwave-induced pyrolysis for achieving efficient photocatalytic degradation of pollutant malachite green dye (MG) in water. Surface morphology studies using high-resolution transmission electron microscopy confirmed the formation of spherical-shaped CDs with an absorbance peak at 350 nm and emission peak at 437 nm in UV-vis and fluorescence spectroscopy, respectively. Surface functional groups, elemental composition, and metal/non-metal co-doping were confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. To understand the photocatalytic performance of Zr-N-S-CDs, various parameters, such as the source of energy, concentration of dye, catalyst dosage, and change in pH, were investigated. MG dye (20 ppm) at a pH 7 with 0.5 mg/mL of Zr-N-S-CDs could be photodegraded efficiently in 90 min under sunlight (99%) compared to dark and artificial light conditions. Moreover, real-time analysis of degradation rate could be conveniently calculated by integrating the colorimetric responses of MG dye with RGB values obtained by the "Color Picker" app of a smartphone. The degradation rate obtained using a smartphone (97.89%) was found to be in agreement with the UV-vis spectroscopy (99%), thus, providing a new, handy, and instrument-free route for speedy and quantitative estimation of the degradation of hazardous MG dye by Zr-N-S-CDs.
通过微波诱导热解合成了太阳光活性蓝色发射的掺锆、氮和硫的碳点（Zr-N-S-CDs），用于实现水中污染物孔雀石绿染料（MG）的高效光催化降解。高分辨率透射电子显微镜的表面形貌研究证实了球形 CDs 的形成，其在紫外-可见光谱和荧光光谱中分别具有 350nm 的吸收峰和 437nm 的发射峰。傅里叶变换红外光谱和 X 射线光电子能谱证实了表面官能团、元素组成和金属/非金属共掺杂。为了了解 Zr-N-S-CDs 的光催化性能，研究了各种参数，如能源来源、染料浓度、催化剂用量和 pH 值的变化。在 pH 7 下，用 20ppm 的 MG 染料和 0.5mg/mL 的 Zr-N-S-CDs 可以在阳光下（99%）高效地在 90 分钟内光降解，而在黑暗和人工光条件下则不行。此外，通过智能手机“颜色选择器”应用程序获得的 RGB 值与 MG 染料的比色响应相结合，可以方便地实时计算降解速率。智能手机获得的降解速率（97.89%）与紫外-可见光谱（99%）一致，因此为 Zr-N-S-CDs 快速定量估计危险 MG 染料的降解提供了一种新的、方便的、无仪器的途径。
