Journal of Environmental Chemical Engineering
·
2019
·
IF 0
Limei Cao,Qian Wang,Ji Yang
A novel ultrafine Pt/Beta catalyst supported on carbon paper was prepared and applied to selective catalytic reduction of NO x by H 2 at a low temperature below 90 °C. Here, 0.8 wt.% Pt/Beta reached approximately 100 % NO conversion at 90 °C under oxygen-rich conditions (1000 ppm NO, 1 % H 2 , and 4 % O 2 ). The influence of the dispersion and particle size of Pt on the catalytic performance was investigated using Polyvinylpyrrolidone (PVP) as a structure directing agent to regulate the Pt particles. The feeding amount of PVP significantly influenced the catalytic activity of the catalysts. When the feeding amount was less than 50 mg, the Pt particle size was smaller, and the dispersion was higher, providing a higher NO conversion. However, when the feeding amount exceeded 50 mg, the dispersion no longer increased, and the activity slightly decreased. N 2 physisorption (BET) confirmed that excessive PVP decreased the specific surface area, which suppressed the catalytic activity of Pt/Beta. Moreover, the NO conversion efficiency was dependent on the dispersion and particle size of Pt and was minimally affected by the surface area of the catalysts. The Pt/Beta catalyst system was deactivated, and an irreversible poisoning phenomenon for SO 2 was observed. Zr, Ce, and V were introduced into the catalyst system as metal auxiliaries . The Ce-modified Pt-Ce/Beta catalyst prepared in this study showed resistance to SO 2 .
研究领域:
环境科学
·
催化化学
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Hengyi Wang,Yong-Fei Li,Xueli Niu,Peiyun Dai,Mingyu Dou,Guang Yang,Fatao Gong,Hongjie Zhu,Hua Yang,Jianmin Dou
Due to the consumption of traditional fossil fuels, human society faces global energy shortages and increasing environmental pollution problems. To address water pollution caused by the abuse of antibiotics and to promote green hydrogen production. In this paper, a Bi 2 WO 6 /CdS S-scheme heterojunction was prepared to realize the photocatalytic levofloxacin (LEV) degradation coupled with hydrogen production reaction. Under the introduction of [Co(bpy) 3 Cl 2 ] (CoBpy) as a molecular photosensitizer, the hydrogen production activity of Bi 2 WO 6 /CdS increased remarkably to 5395.9 μmol g −1 h −1 , meanwhile, the degradation rate of LEV could reach 87.5 %, which was much higher than that of the pure phase material and exhibited excellent stability over five cycles. The enhanced photocatalytic activity originates from the S-scheme heterojunction mechanism that enables the oxidizing and reducing abilities of the material to be fully exploited, meanwhile the sensitization of CoBpy further optimizes the charge transfer pathway, which realizes the combination of visible-light-driven wastewater treatment and green hydrogen production. Our findings provide an efficient and safe approach to environmental remediation and green energy production for a sustainable energy future.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Qian Wu,Xinping He,Chenyi Cui,Chenchen Jiao,Baojin Qi,Jinjia Wei
Mixed matrix membranes (MMMs) incorporating metal–organic frameworks (MOFs) hold significant promise for gas separation applications. However, the inherent disparity between the organic polymer matrix and the inorganic fillers frequently leads to interfacial incompatibility issues. In this study, we adopted an in-situ interfacial crosslinking strategy to fabricate MMMs incorporating NH 2 -Zn 2 (Bim) 4 nanosheets that simultaneously act as nanofillers and reactive crosslinkers. Specifically, during the thermal imidization reaction process, the amino groups of NH 2 -Zn 2 (Bim) 4 not only establish hydrogen bonding interactions with the carbonyl groups of polyamic acid (PAA) (the precursor of polyimide), but undergo dehydration reactions with carboxyl groups, leading to the formation of stable amide linkages. Meanwhile, the aromatic structure of the BI units, a key monomer of polyimide, closely resembles that of the ligands of NH 2 -Zn 2 (Bim) 4 , which can establish π-π stacking interactions, further improving the interfacial compatibility between the polymer matrix and MOF fillers. Among the prepared samples, MMMs incorporating 33.3 wt% NH 2 -Zn 2 (Bim) 4 nanosheets exhibit the maximum H 2 permeability of 680.5 Barrer, and its H 2 /N 2 and H 2 /CO 2 selectivities were 18.7 and 13.3, respectively, which were close to or even exceeded the Robeson upper bound. The proposed in-situ interfacial engineering based on chemical crosslinking provides a novel and effective route for fabricating high-performance MMMs with enhanced interfacial compatibility, demonstrating great potential for hydrogen separation applications.
研究领域:
材料科学
·
膜技术
·
气体分离
·
化学工程
·
纳米复合材料
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DOI
高影响因子
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 16
·5652-5659
·
IF 4.099
Yong-Jun Yuan,Gaoliang Fang,Daqin Chen,Yanwei Huang,Ling-Xia Yang,Da-Peng Cao,Jingjing Wang,Zhen-Tao Yu,Zhi-Gang Zou
Expanding the photoresponse range of TiO2-based photocatalysts is of great interest for photocatalytic H2 production. Herein, noble-metal-free CuInS2 quantum dots were employed as a novel inorganic dye to expand the visible light absorption of TiO2/MoS2 for solar H2 generation. The as-prepared CuInS2/TiO2/MoS2 photocatalysts exhibit broad absorption from the ultraviolet to near-infrared region. Under visible light irradiation (λ > 420 nm), the CuInS2/TiO2/MoS2 photocatalyst with 0.6 mmol g−1 CuInS2 and 0.5 wt% MoS2 showed the highest H2 evolution rate with a value of 1034 μmol h−1 g−1. Moreover, a considerable H2 evolution rate of 141 μmol h−1 g−1 was obtained under the irradiation of the optimized CuInS2/TiO2/MoS2 photocatalyst with >500 nm light. The reaction mechanism of the CuInS2/TiO2/MoS2 photocatalyst for photocatalytic H2 evolution was investigated in detail by photoluminescence decay study, and the results showed that the photoexcited electrons of CuInS2 can be transferred efficiently through TiO2 to MoS2 and then react with the absorbed protons to generate H2. The reported sensitization strategy tremendously improves the visible light absorption capacity and the photocatalytic performance of TiO2-based photocatalysts.
研究领域:
材料科学
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光催化
·
能源化学
·
纳米材料
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半导体物理
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太阳能转化
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DOI
高影响因子
APPLIED CLAY SCIENCE
·
2019
·
IF 3.89
Xiang Hu,Zhu Shu,Hui Guo,Jun Zhou,Tiantian Li,Yigen Tan,Zihao Liao,Wenbin Wang,Zhengliang Zhao
Nanostructure-tailoring and composite-construction are two effective strategies to optimize polymeric carbon nitride (PCN) for advanced photocatalysis . Herein, a vapor deposition process was adopted to grow PCN nanosheets on the surface of the cheap mineral metakaolin , achieving both the nano-structuring of PCN and the synchronous construction of metakaolin/nano-PCN composite. It showed a substantially improved photocatalytic H 2 evolution activity 3.8 times higher than the traditional bulk PCN under visible light. Performance gains benefit from the natural electronegativity of metakaolin and the nanosizing of PCN, which synergistically facilitate the separation and utilization of photoinduced charge carriers. This work may inspire not only the utilization of various clay minerals but also the nano-tailoring and composite-construction of PCN.
研究领域:
材料科学
·
环境科学
·
化学工程
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Xiutong Yan,Biyun Lin,Chuangyu Ning,Xin Wang,Zhihong Chen
CdS is a promising candidate for visible-light-driven photocatalytic H 2 -evolution, but its practical application is still limited by self-photo-corrosion and noble co-catalysts needing. Herein, CdS/NiCo-MOFs (CM) heterojunction was synthesized by an in-situ hydrothermal method , where NiCo-MOFs (BMOFs) acted as platform to inhibit the aggregation of CdS nanoparticles . Furthermore, BMOFs provided dual-reaction sites to improve the photocatalytic H 2 -evolution speed and suppress the photo-corrosion of CdS by taking its Ni-linker as catalytic active sites for water splitting and Co-linker as hole trapping sites to suppress the self-oxidation between S 2− and holes. Therefore, the optimal CM-20% exhibited a remarkable photocatalytic H 2 -evolution rate of 1.810 mmol g −1 h −1 under sunlight irradiation, which is 4.55 times higher than that of CdS. Moreover, CM-20% maintained this high photocatalytic H 2 -evolution rate for 100 h reaction, which for CdS is just 50 h. This research provides insight into designing high-efficiency and photo-stable sulfide-based photocatalyst systems for H 2 -evolution.
研究领域:
材料科学
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能源化学
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DOI
高影响因子
Journal of Energy Chemistry
·
2024
·
IF 14
Dong Zhang,Minghui Zhu,Ran Qin,Peixian Chen,Maoye Yin,Dafeng Zhang,Junchang Liu,Hengshuai Li,Xipeng Pu,Peiqing Cai
Rational design of photocatalyst to maximize the use of sunlight is one of the issues to be solved in photocatalysis technology. In this study, the CuFe 2 O 4 @C/Cd 0.9 Zn 0.1 S (CFO@C/CZS) S-scheme photocatalyst with photothermal effect was synthesized by ultrasonic self-assembly combined with calcination. The dark CFO@C absorbed visible light and partly converted into heat to promote the hydrogen evolution reaction. The presence of heterojunctions inhibited the photogenerated electron-hole recombination. The graphite-carbon layer provided a stable channel for electron transfer, and the presence of magnetic CFO made recycle easier. Under the action of photothermal assistance and heterojunction, the hydrogen evolution rate of the optimal CFO@C/CZS was 80.79 mmol g −1 h −1 , which was 2.55 times and 260.61 times of that of pure CZS and CFO@C, respectively. Notably, the composite samples also exhibit excellent stability and a wide range of environmental adaptability. Through experimental tests and first-principles simulation calculation methods, the plausible mechanism of photoactivity enhancement was proposed. This work provided a feasible strategy of photothermal assistance for the development of heterojunction photocatalysts with distinctive hydrogen evolution.
研究领域:
材料科学
·
环境科学
·
能源科学
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高影响因子
DIAMOND AND RELATED MATERIALS
·
2023
·
IF 4.1
Fengling Wang,Sen Jin,Yaqiong Du,Qixun Xia,Libo Wang,Aiguo Zhou
Mo 2 C T x is a novel co-catalyst to enhance the photocatalytic performance of CdS for H 2 production. The surface of Mo 2 C T x is usually terminated by fluorine anion because it is generally made by the etching of fluoride-containing solution. Here we report, a novel method to prepare highly pure MXene with Br termination by the etching of pure HBr at 220 °C for 3 d, or the HBr solution mixed with LiBr, NaBr, KBr or NH 4 Br at 180 °C for 24 h. The pure HBr etching needs higher temperature and longer time to make pure Mo 2 C T x , however, which result lager interlayer space and more active sites. All the Mo 2 C T x samples show high co-catalytic performance to enhance the photocatalytic performance of CdS for H 2 production. The H 2 production rate of CdS combined with HBr etched sample was 17,566 μmol g −1 h −1 , similar with the sampled combined with traditionally HF etched sample. This is the first report to prepare MXene by etching of Br containing solution. The Mo 2 C T x made by this method is terminated by Br/O without F, and show excellent co-catalytic properties.
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高影响因子
OPTICAL MATERIALS
·
2023
·
IF 3.9
Zihuan Wei,Lina Kong,Qiang Wang,Jianping Xu,Lan Li
Conjugated structure modification is an effective strategy for improving the photocatalytic activity of graphitic carbon nitride (g-C 3 N 4 ). Herein, we introduce p-π conjugated to g-C 3 N 4 by surface grafting of hydroxyl (-OH) groups through a facile hydrothermal process to improve the photo-carriers generation and separation. Experiments and DFT calculations indicate that the hydrothermal treatment decorated –OH groups onto the C sites of g-C 3 N 4 and formed p-π conjugated structure between the 2p orbitals of the O and the π orbitals of the tri-s-triazine unit. The extended p-π electrons delocalization of g-C 3 N 4 increases the concentration of the carriers, and the –OH groups serve as electrons transport channels facilitating the separation of the carriers. Consequently, –OH grafted g-C 3 N 4 with hydrothermal treated at 120 °C exhibits the highest and recyclable H 2 evolution rates of 2.3 mmol h −1 g −1 under simulated sunlight irradiation, which outperform pristine g-C 3 N 4 1.42 times. This work proposes a new mechanism of the p-π conjugate of –OH decorated g-C 3 N 4 for improving charge carriers formation and separation, and provides a mild strategy to engineer the other conjugated molecular structures.
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高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Hongmiao Zhou,Jiayi Tian,Ruoyu Wang,Difu Zhan,Peng Liu,Ruolin Chen,Yizhong Huang,Zhifeng Liu,Changcun Han
Photocatalytic hydrogen (H 2 ) evolution is expected to be a promising approach to generating a clean energy source (H 2 ) with low carbon emissions, which is vital to solving environmental degradation and energy shortages. The critical challenge to designing highly efficient photocatalysts is the fast recombination of photo-generated carriers; thus, we select Ti 3 C 2 Cl 2 MXene with excellent metal characteristics to serve as a co-catalyst and combine with g-C 3 N 4 . The Ti 3 C 2 Cl 2 /g-C 3 N 4 composites exhibit an enhanced photocatalytic hydrogen evolution activity (maximum 155.9 μmol h −1 ) while they hardly perform photocatalytic activities. The photoluminescence (PL) spectra shows that Ti 3 C 2 Cl 2 MXenes help boost the separation of photo-generated carriers of g-C 3 N 4 and finally strengthen the photocatalytic hydrogen evolution performance. The ultraviolet–visible (UV–vis) spectra illustrate that composites perform a strengthened light absorption, which fits well with the results in the hydrogen evolution experiment. Thus, we fabricated a highly efficient photocatalyst through a safer molten salt approach without hydrofluoric acid (HF). We believe this work will offer a safer approach to manufacturing catalysts decorated with MXenes for highly efficient photocatalytic H 2 evolution.
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高影响因子
GREEN CHEMISTRY
·
2023
·Vol. 25
·期 5
·1823-1834
·
IF 9.8
Ying Duan,Chi Zhang,Dongsheng Deng,Dong Sui,Xiaohan Gao,Yanliang Yang
The rearrangement of furan rings for valuable chemicals is an important topic for biomass conversion. In this study, 2,5-di(hydroxymethyl)furan (BHMF) was selectively converted to 6-methyldihydro-2H-pyran-3(4H)-one (MDPO) and 1-hydroxy-2,5-hexanedione (HHD) under atmospheric H2 pressure in water. The selectivity to MDPO or HHD could be regulated by a catalyst. The parameters (temperature, pH, catalyst loading, and BHMF concentration) for the transformation of BHMF were studied. The selectivity for the transformation of BHMF was very sensitive to the reaction conditions, especially for the conversion of BHMF to MDPO. 68% selectivity to MDPO on Pd/C and 72% selectivity to HHD on Rh/C were achieved under the optimized conditions. Both Pd/C and Rh/C could be reused at least 5 times without the loss of activity. The fresh and used Pd/C and Rh/C were characterized by XRD, XPS, SEM, TEM, EDS mappings and ICP-OES to study the changes during the reaction. The reaction process was studied through controlled experiments, and 6-methylene-2H-pyran-3(6H)-one (MEPO) and 6-hydroxy-6-methyl-2H-pyran-3(6H)-one (HMPO) were identified as intermediates. A reasonable reaction mechanism was proposed and the different selectivity to MDPO and HHD was well explained based on the controlled experiments and DFT calculations. The conditional sensitivity for the selectivity to MDPO and HHD could also be interpreted by the proposed reaction pathway.
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高影响因子
FUEL
·
2023
·
IF 7.4
Qi Rong,Wenkai Huang,Fuhua Xu,Yanlan Wang,Changlong Wang,Xiang Liu
In spite of significant developments are accomplished in the exploration of H 2 and O 2 evolution upon water electrolysis/photolysis, this remains a challenge to design and develop ideal catalytic systems for this reaction and to isolate H 2 from H 2 -O 2 mixture with membranes. Herein, a series of ZIF-67-supported transition metal nanoparticles (TMNPs/ZIF-67), including Pt, Ir, Pd, Rh, Au and Ag, via immobilization of ultrafine TMNPs at the surface of ZIF-67, have been designed and developed for the selective H 2 generation from NH 3 BH 3 hydrolysis and O 2 evolution upon H 2 O 2 decomposition. In particular, the optimized nanocatalyst Pt/ZIF-67 presents the super-high catalytic property in the both H 2 evolution upon NH 3 BH 3 hydrolysis (689 mol(H 2 )·mol Pt -1 ·min −1 ) and O 2 evolution upon H 2 O 2 decomposition (979 mol(O 2 )·mol Pt -1 ·min −1) at 30 °C. Importantly, the selective “on–off” control for demand-based H 2 generation from NH 3 BH 3 hydrolysis was successfully realized by Zn 2+ /EDTA-2Na system. This highly efficient Pt/ZIF-67 proposed a new method for the promising potential application of ammonia borane and hydrogen peroxide as an economic and safe H 2 resp. O 2 carrier for fuel cell.
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高影响因子