Rolivhuwa Mulovhedzi, Kholiswa Yokwana, Timothy O. Ajiboye, Adeniyi S. Ogunlaja, Sabelo D. Mhlanga
{"title":"A novel structured graphene oxide@microalgae nanohybrids as adsorbents for removal of Cr(VI) ions in aqueous solutions","authors":"Rolivhuwa Mulovhedzi, Kholiswa Yokwana, Timothy O. Ajiboye, Adeniyi S. Ogunlaja, Sabelo D. Mhlanga","doi":"10.1007/s10450-025-00614-7","DOIUrl":null,"url":null,"abstract":"<div><p>Novel structured graphene oxide@microalgae-based nanohybrids have been prepared by incorporating green microalgae biomass (Algae) with graphene oxide (GO) or N-doped graphene oxide (NGO) in different ratios (e.g., 3:1, 1:1 and 1:3). Biogenic GO-Algae and NGO-Algae nanohybrids were synthesized <i>via</i> a self-assembly method. Morphological and structural characterizations and adsorption performance of the nanostructured material towards Cr(VI) species were studied extensively. The removal of Cr(VI) species by GO-Algae and NGO-Algae nanohybrids was highly pH dependent, with the maximum adsorption removal occurring at pH 2. The results indicate that the adsorption of Cr(VI) by GO-Algae and NGO-Algae nanohybrids was as follows: GO@Algae-3:1 (90.5%) < GO@Algae-1:1 (98.7%) < GO@Algae-1:3 (99.6%) and NGO@Algae-3:1 (79.2%) < NGO@Algae-1:1 (82.3%) < NGO@Algae-1:3 (92.6%), respectively. The GO: Algae-1:3 and NGO: Algae-1:3 nanohybrids with a high microalgae content ratio exhibited high maximum removal, owing to the presence of more active sites within their lattice compared to their counterparts. On the other hand, pseudo-first-order, pseudo-second-order, intraparticle diffusion, Langmuir, and Freundlich models adequately simulated adsorption mechanisms, suggesting that the adsorption process involved a combination of external mass transfer and chemisorption, with electrostatic and complexation interactions being the dominant mechanisms for Cr(VI) removal. Additionally, GO@Algae-1:3 and NGO@Algae-1:3 displayed outstanding reusability. Therefore, these structured graphene@microalgae-based nanohybrids can simultaneously serve as adsorbents for Cr(VI) removal from wastewater and contaminated water sources.</p></div>","PeriodicalId":458,"journal":{"name":"Adsorption","volume":"31 4","pages":""},"PeriodicalIF":3.0000,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10450-025-00614-7.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Adsorption","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s10450-025-00614-7","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Novel structured graphene oxide@microalgae-based nanohybrids have been prepared by incorporating green microalgae biomass (Algae) with graphene oxide (GO) or N-doped graphene oxide (NGO) in different ratios (e.g., 3:1, 1:1 and 1:3). Biogenic GO-Algae and NGO-Algae nanohybrids were synthesized via a self-assembly method. Morphological and structural characterizations and adsorption performance of the nanostructured material towards Cr(VI) species were studied extensively. The removal of Cr(VI) species by GO-Algae and NGO-Algae nanohybrids was highly pH dependent, with the maximum adsorption removal occurring at pH 2. The results indicate that the adsorption of Cr(VI) by GO-Algae and NGO-Algae nanohybrids was as follows: GO@Algae-3:1 (90.5%) < GO@Algae-1:1 (98.7%) < GO@Algae-1:3 (99.6%) and NGO@Algae-3:1 (79.2%) < NGO@Algae-1:1 (82.3%) < NGO@Algae-1:3 (92.6%), respectively. The GO: Algae-1:3 and NGO: Algae-1:3 nanohybrids with a high microalgae content ratio exhibited high maximum removal, owing to the presence of more active sites within their lattice compared to their counterparts. On the other hand, pseudo-first-order, pseudo-second-order, intraparticle diffusion, Langmuir, and Freundlich models adequately simulated adsorption mechanisms, suggesting that the adsorption process involved a combination of external mass transfer and chemisorption, with electrostatic and complexation interactions being the dominant mechanisms for Cr(VI) removal. Additionally, GO@Algae-1:3 and NGO@Algae-1:3 displayed outstanding reusability. Therefore, these structured graphene@microalgae-based nanohybrids can simultaneously serve as adsorbents for Cr(VI) removal from wastewater and contaminated water sources.
期刊介绍:
The journal Adsorption provides authoritative information on adsorption and allied fields to scientists, engineers, and technologists throughout the world. The information takes the form of peer-reviewed articles, R&D notes, topical review papers, tutorial papers, book reviews, meeting announcements, and news.
Coverage includes fundamental and practical aspects of adsorption: mathematics, thermodynamics, chemistry, and physics, as well as processes, applications, models engineering, and equipment design.
Among the topics are Adsorbents: new materials, new synthesis techniques, characterization of structure and properties, and applications; Equilibria: novel theories or semi-empirical models, experimental data, and new measurement methods; Kinetics: new models, experimental data, and measurement methods. Processes: chemical, biochemical, environmental, and other applications, purification or bulk separation, fixed bed or moving bed systems, simulations, experiments, and design procedures.