Nizam Nurul Umairah M, Hanafiah Marlia M, Mahmoudi Ebrahim, Mohammad Abdul Wahab
Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia.
Centre for Tropical Climate Change System, Institute of Climate Change, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia.
Sci Rep. 2023 Aug 7;13(1):12777. doi: 10.1038/s41598-023-40069-w.
The potentials of biomass-based carbon quantum dot (CQD) as an adsorbent for batch adsorption of dyes and its photocatalytic degradation capacity for dyes which are congo red (CR) and methylene blue (MB) have been conducted in this study. The CQDs properties, performance, behaviour, and photoluminescence characteristics were assessed using batch adsorption experiments which were carried out under operating conditions including, temperature, pH and dosage. The morphological analysis revealed that CQDs are highly porous, uniform, closely aligned and multi-layered. The presence of hydroxyl, carboxyl and carbonyl functional groups indicated the significance of the oxygenated functional groups. Spectral analysis of photoluminescence for CQDs confirmed their photoluminescent quality by exhibiting high excitation intensity and possessing greenish-blue fluorescence under UV radiation. The removal percentage of the dyes adsorbed for both CR and MB dyes was 77% and 75%. Langmuir isotherm and pseudo-second-order models closely fitted the adsorption results. Thermodynamics analysis indicated that the adsorption process was exothermic and spontaneous, with excellent reusability and stability. The degradation efficiency of CQDs on both dyes was more than 90% under sunlight irradiation and obeyed the first-order kinetic model. These results demonstrated CQDs to be an excellent adsorbent and outstanding photocatalyst for organic dye degradation.
本研究探讨了生物质基碳量子点（CQD）作为吸附剂对刚果红（CR）和亚甲基蓝（MB）等染料进行批量吸附的潜力及其对染料的光催化降解能力。通过在包括温度、pH值和用量等操作条件下进行的批量吸附实验，评估了CQD的性质、性能、行为和光致发光特性。形态分析表明，CQD具有高度多孔、均匀、紧密排列和多层的结构。羟基、羧基和羰基官能团的存在表明了含氧官能团的重要性。CQD的光致发光光谱分析通过在紫外辐射下表现出高激发强度并具有蓝绿色荧光，证实了其光致发光性质。CR和MB染料的吸附去除率分别为77%和75%。朗缪尔等温线和准二级模型与吸附结果拟合良好。热力学分析表明，吸附过程是放热的且自发的，具有优异的可重复使用性和稳定性。在阳光照射下，CQD对两种染料的降解效率均超过90%，并符合一级动力学模型。这些结果表明，CQD是一种用于有机染料降解的优异吸附剂和出色的光催化剂。
