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- Preparation of cobalt based organic metal framework ZIF-67 catalyst for activating PMS and its catalytic system for rapid degradation of various high concentration dyesPublication . Cai, Yangyi; Liu, Xiaocan; Yang, Weiye; Peng, Hongyan; Meng, Lijian; Zhao, ShihuaPersistent organic pollutants pose significant long-term risks to environmental and human health due to their carcinogenic, mutagenic, and teratogenic properties. This study focuses on the efficient activation of peroxymonosulfate (PMS) through the rational design of a cobalt-based metal–organic framework (ZIF-67) catalyst, enabling rapid degradation of high-concentration dye pollutants. By optimizing the molar ratio of 2-methylimidazole (2-MeIM) to Co(NO3)2·6H2O and employing a hydrothermal synthesis method, we fabricated ZIF-67 (4 : 1) with high crystallinity, large specific surface area (1656.68 m2 g−1), and stable degradation performance. The ZIF-67 (4 : 1)/PMS system achieved complete degradation of 20 mg L−1 and 100 mg per L Rhodamine B (RhB) within 60 seconds and 6 minutes, respectively, surpassing recent reported efficiencies. The system also maintained high activity over a broad pH range (3–9). Radical quenching experiments and electron paramagnetic resonance (EPR) analysis identified sulfate radicals (˙SO4−4) and singlet oxygen (1O2) as the dominant reactive species. Furthermore, the catalyst exhibited excellent recyclability with no significant loss in activity after five consecutive cycles. This work provides a facile and scalable strategy for preparing highly active cobalt-based catalysts, demonstrating great potential for practical applications in industrial wastewater treatment and environmental remediation.
- Dual-Regulated Ru by Alloying and Metal-Substrate Interaction for Energy-Efficient Hydrazine Oxidation-Paired Hydrogen ProductionPublication . Zhang, Qijing; Wang, Jingshu; Li, Haibo; Zeng, Suyuan; Li, Rui; Yao, Qingxia; Chen, Hongyan; Meng, Lijian; Qu, Konggang; Meng, LijianOverall water splitting (OWS) is the most potential method for large-scale hydrogen production, but the high-potential and sluggish oxygen evolution reaction (OER) greatly impedes its efficacy. Coupling the low-potential hydrazine oxidation reaction (HzOR) with the cathodic hydrogen evolution reaction (HER) has drawn widespread attention with energy-saving advantage and safe products, which necessitates the elaborate design of advanced bifunctional electrocatalysts. Herein, only using two complexes of Ru and Pd with 2,2′-bipyridine, the novel RuPd alloy/N-codoped carbon (RuPd/NC) composite was originally synthesize by direct mixing and pyrolysis, showing superior dual activity for HER and HzOR. Particularly, to deliver the current density of 10 mA cm−2, RuPd/NC merely needs the potentials of −8 and −42 mV for alkaline HER and HzOR, far outperforming Pt/C and being most advanced among the previously studied counterparts. Moreover, the two-electrode overall hydrazine splitting (OHzS) needs ultrasmall voltages of 0.042 and 0.239 V to achieve 10 and 100 mA cm−2, displaying great energy-saving feature. Moreover, the better activity for neutral HER, HzOR and OHzS on RuPd/NC was also found compared with Pt/C. The theoretical simulations uncover the water dissociation at Ru site with the greatly reduced energy barrier followed by the H desorption on the adjacent Pd site for HER, and the optimum activation energy on Ru site for HzOR, crediting to the synergistic regulation of alloying effect and metal-substrate interaction.
- Atomic Dispersion of Scandium in Electrochemically Reduced Copper Oxide Nanosheets for Efficient Electrocatalytic CO2 Reduction to C2+ ProductsPublication . Zhao, Yang; Zeng, Binwen; Huang, Haoliang; Yang, Huanhuan; Yu, Zhipeng; Song, Chao; Wang, Jingwei; Xu, Kaiyang; Xiang, Xinyi; Wang, Wei; Lin, Fei; Meng, Sheng; Meng, Lijian; Cui, Zhiming; Liu, LifengConverting CO2 into value-added chemicals and fuels through electrochemical CO2 reduction reaction (CO2RR) has been acknowledged as a disruptive technology for chemical industry and an important means to realizing carbon neutrality. However, it remains challenging to achieve high selectivity for C2+ products at a large current density with a low overpotential. Herein, we report a scandium (Sc) single-atom-doped CuO nanosheet (Sc1CuO NS) electrocatalyst for efficient and durable CO2-to-C2+ conversion. The optimal Sc1CuO NS catalyst achieves a maximal C2+ Faradaic efficiency of 73 ± 1.8 % at 475.2 mA cm−2 under an ultralow potential of −0.6 V versus the reversible hydrogen electrode (RHE) and maintains stable CO2-to-C2+ conversion at ∼206 mA cm−2 with a > 60 % Faradaic efficiency for 47 h without degradation. In-situ spectroscopy measurements combined with density functional theory (DFT) calculations reveal that the electron transfer from Sc to Cu enhances the activation of CO2 to *CO. Moreover, the in-situ electrochemical reduction of CuO generates abundant undercoordinated Cu0 sites, featuring tensile-strained Sc-(O)-Cu motifs, which serve as active centers that reduce the reaction barrier for Csingle bondC coupling. This work highlights the importance of rare-earth doping combined with in-situ electrochemical surface reconstruction of CuO as an effective catalyst design strategy to boost CO2-to-C2+ conversion performance.
- A novel ternary Z-scheme g-C3N4/CQDs/FeVO4 heterojunction for photodegradation of levofloxacin via peroxymonosulfate activationPublication . Li, Yunuo; Han, Pengda; Zhang, Dongzhe; Zhang, Wenzhi; Chai, Dong-feng; Meng, Lijian; Meng, Lijian; Liming, Bai; Zhao, Ming; Dong, GuohuaCurrently, it is still a significant challenge for photodegradation of the emerging pollutants using g-C3N4 (CN) due to their interior visible light responsibility and rapid recombination of e-/h+. Herein, a novel Z-scheme g-C3N4/CQDs/FeVO4 (CCF) photocatalyst was synthesized by initially preparing hollow tubular g-C3N4/CQDs (CC) and then anchoring FeVO4 on CC. The morphology, structural composition and photoelectrochemical performance of the CCF were investigated by comprehensive characterization such as FT-IR, XPS, XRD, SEM and photoelectrochemical performance tests. The CCF shows superior photodegradation capability toward LFX via activation of peroxymonosulfate (PMS), resulting in a photodegradation efficiency ∼ 97.3 % in the optimal conditions. Apart from the strengthened light responsibility, improved BET specific surface area and porous texture of CCF, the improved photodegradation properties can be ascribed to the formed Z-scheme heterojunction between CC and FeVO4, which can ameliorate the separation efficiency of e-/h+ and accelerate their transfer rate. The addition of CQDs can also serve as a channel for promoting the rapid transfer of photogenerated e-/h+. The photodegradation processes of LFX including generation of reactive oxygen species (ROS) and removal pathways were systematically explored by using radical capturing assays, electron spin resonance (ESR) tests and liquid chromatography-mass spectrometry (LC-MS) techniques. To sum up, this study provides an innovative method for regulating the photocatalytic activity of g-C3N4 via constructing Z-scheme heterostructures and incorporating CQD to degrade emerging contaminants.
- Multimetallic layered double hydroxides as efficient and durable oxygen evolution catalysts for anion exchange membrane water electrolysis at high current densitiesPublication . Yaowen Xu, Kaiyang Xu, Hao Tan, Haoliang Huang, Fei Lin, Chenyue Zhang, Jingwei Wang, Run Ran, Jinfeng Zeng, Zhipeng Yu, Sitaramanjaneya Mouli Thalluri, Lijian Meng, Dehua Xiong and Lifeng Liu
- Confined RuP2 Nanoparticles in N,P,S-tridoped Carbon as Superior Electrocatalyst for pH-Wide Hydrogen EvolutionPublication . Yu Sun, Haibo Li, Suyuan Zeng, Rui Li, Qingxia Yao, Hongyan Chen, Yinghua Wang, Konggang Qu, Lijian Meng
- Ultrafine Ru on Reduced Graphene Oxide-La2O3 Binary Support for Highly Efficient Hydrogen Evolution ReactionPublication . iaying Zhang; Qijing Zhang; Jingyi Qiu; Xiaoying Zhang; Zhiyuan Zhu; Hongyan Chen; Konggang Qu; Lijian Meng
- A novel ternary Z-scheme g-C3N4/CQDs/FeVO4 heterojunction for photodegradation of levofloxacin via peroxymonosulfate activationPublication . Yunuo Li, Pengda Han, Dongzhe Zhang, Wenzhi Zhang, Dong-feng Chai, Lijian Meng, Liming Bai, Ming Zhao, Guohua Dong
- Covalent organic framework assisted low-content ultrafine ru on porous N-doped carbon for efficient hydrogen evolution reactionPublication . Kong-Gang Qu; Zhi-Fei Chen; Li-Hui Wang; Hai-Bo Li; Su-Yuan Zeng; Rui Li; Li-Jian Meng; Hong-Yan Chen; Qing-Xia Yao(Excerpt) Pt-based materials are the benchmarked catalysts in the cathodic hydrogen evolution reaction (HER) of water splitting; the prohibitive cost and scarcity of Pt immensely impede the commercialization of hydrogen energy. Ru has aroused significant concern because of its Pt-like activity and much lower price. However, it’s still a top priority to minimize the Ru loading and pursue the most superior cost performance. Herein, N-rich covalent organic framework (COF) was employed to assist the preparation of ultrafine Ru, including nanoclusters and single atoms loaded onto porous N-doped carbon by a simple impregnation-pyrolysis process with a low Ru content of 6.60 wt%, exhibiting superior HER activity with mass activity of 21.86 and 11.52 A mg-1 Ru (@100 mV) in alkaline and acidic conditions, separately 14.7 and 2.12 times higher than that of commercial Pt/C.
- Microwave-assisted synthesis of hierarchical BiOBr/BiOF Z-scheme heterojunction for activating peroxymonosulfate toward photodegradation of the recalcitrant levofloxacinPublication . Guohua Dong; Dongzhe Zhang; Xinjia Zhang; Zhuangfang Zhang; Dong-feng Chai; Lijian Meng; Jinlong Li; Ming Zhao; Wenzhi ZhangHerein, a novel Z-scheme BiOBr/BiOF heterojunction was synthesized via one-step microwave-assisted hydrothermal method, which was integrated with peroxymonosulfate (PMS) to design a sulfate radical (•SO4−) based advanced oxidation processes (AOPs) system through PMS activation (BiOBr/BiOF-PMS) toward Levofloxacin (LFX) photodegradation. In order to achieving an optimal degradation efficiency, the formed BiOBr/BiOF-PMS was systematically investigated and the operational parameters for LFX photodegradation were thoroughly optimized. Thereby, the optimal BiOBr/BiOF exhibits a higher photodegradation efficiency of 89.8 % toward LFX via PMS activation compared to others including PMS alone, BiOBr, BiOF and BiOBr/BiOF with varied ratios. Furthermore, the BiOBr/BiOF has superior stability for multiple cycles and universal applicability for degrading various contaminants. This can mainly be attributed that the formed heterojunction between BiOBr and BiOF and the enhanced concentration of oxygen vacancies (OVs) of BiOBr/BiOF heterojunction, which can synchronously promote the separation and transmission of the photogenerated charges (e−/h+) and thereby lead to more reactive oxygen species (ROS). As well, the expanded optical responsiveness and increased specific surface area of BiOBr/BiOF are also mainly responsible for the improved photodegradation capability. Free radical capture experiments and ESR technique verify that the •O2− is the primary ROS and •SO4− and •OH play subordinative role. The photodegradation pathways of LFX were unraveled based on the identified intermediates with a liquid-chromatography-mass (LC-MS) technique. Consequently, this study offers a novel route by developing Bi-based heterojunction photocatalyst to activate PMS for refractory antibiotic photodegradation.