Bhattacharjee Baishali, Hazarika Berileena, Ahmaruzzaman Mohammed
Department of Chemistry, National Institute of Technology, Silchar, Assam, 788010, India.
Environ Sci Pollut Res Int. 2023 Nov;30(52):112591-112610. doi: 10.1007/s11356-023-30297-y. Epub 2023 Oct 14.
Conversion of carbon-rich waste biomass into valuable products is an environmentally sustainable method. This study accentuates the synthesis of novel SnO QDs@g-CN/biochar using low-cost sawdust by applying the pyrolysis method. Morphology, structure, and composition of the synthesized SnO QDs@g-CN/biochar nanocomposite were characterized using SEM (scanning electron microscope), TEM (transmission electron microscope), XRD (X-ray diffraction), XPS (X-ray photoelectron spectroscopy), FT-IR (infrared spectroscopy) and PL (photoluminescence) spectroscopy. The average diameter of the SnO QDs was measured from TEM and found to be 6.79 nm. Optical properties of the as-synthesized SnO QDs@g-CN/biochar were characterized using UV-visible spectroscopy. The direct band gap of synthesized SnO QDs@g-CN/biochar nanocomposite was calculated from Tauc's plot and found to be 2.0 eV. The fabricated SnO QDs@g-CN/biochar photocatalyst exhibited outstanding photocatalytic degradation efficiency for the removal of Rose Bengal (RB) and Methylene Blue (MB) dye through the Advanced Oxidation Process (AOP). The synthesized photocatalyst showed a degradation efficiency of 95.67% for the removal of RB under optimum conditions of 0.3 mL HO, photocatalyst dosage of only 0.06 gL, and 15 ppm initial RB concentration within 80 min, and 94.5% for the removal of MB dye with 0.5 mL of HO, 0.08 gL of the fabricated photocatalyst and 6 ppm of initial MB concentration within 120 min. The photodegradation pathway followed the pseudo-first-order reaction kinetics with a rate constant of 0.00268 min and 0.00163 min for RB and MB respectively. The photocatalyst can be reused up to the 4 cycle with 80% efficiency.
将富含碳的废弃生物质转化为有价值的产品是一种环境可持续的方法。本研究强调通过热解方法，利用低成本锯末合成新型的SnO量子点@g-CN/生物炭。使用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X射线衍射（XRD）、X射线光电子能谱（XPS）、红外光谱（FT-IR）和光致发光（PL）光谱对合成的SnO量子点@g-CN/生物炭纳米复合材料的形貌、结构和组成进行了表征。从TEM测量得出SnO量子点的平均直径为6.79纳米。使用紫外可见光谱对合成的SnO量子点@g-CN/生物炭的光学性质进行了表征。由Tauc曲线计算得出合成的SnO量子点@g-CN/生物炭纳米复合材料的直接带隙为2.0电子伏特。制备的SnO量子点@g-CN/生物炭光催化剂通过高级氧化过程（AOP）对去除玫瑰红（RB）和亚甲基蓝（MB）染料表现出优异的光催化降解效率。在0.3毫升过氧化氢、光催化剂用量仅为0.06克/升以及初始RB浓度为15 ppm的最佳条件下，合成的光催化剂在80分钟内对RB的去除降解效率为95.67%；在0.5毫升过氧化氢、0.08克/升的制备光催化剂和6 ppm初始MB浓度的条件下，在120分钟内对MB染料的去除率为94.5%。光降解途径遵循准一级反应动力学，RB和MB的速率常数分别为0.00268分钟⁻¹和0.00163分钟⁻¹。该光催化剂可以重复使用多达4个循环，效率达80%。
