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Journal ArticleDOI: 10.1016/J.JHAZMAT.2020.124128

Construction of NH2-MIL-125(Ti)/CdS Z-scheme heterojunction for efficient photocatalytic H2 evolution.

05 Mar 2021-Journal of Hazardous Materials (Elsevier)-Vol. 405, pp 124128
Abstract: Designing efficient semiconductor-based photocatalysts for hydrogen production is a challenging but promising prospect in energy conversion. Herein, a novel Z-scheme CdS/NH2-MIL-125(Ti) heterojunction is successfully fabricated through a facile solvethermal method. The detailed characterizations reveal that CdS nanoparticles are in-suit archored on NH2-MIL-125(Ti) nanoplates. Benefited from the intrinsic band alignment and intimate contact of two species, this established structure gives a positive effect regarding charge separation. In consequence, the optimal CdS/NH2-MIL-125(Ti) nanocomposites exhibit excellent photocatalytic performance with hydrogen evolution rate of 6.62 mmol·h−1·g−1 under visible light illumination, which was 3.5 times higher than that of the pristine CdS. We believe that this work will provide a new avenue to develop high-efficiency heterojunction catalyst for solar-driven energy conversions and other application.

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Topics: Heterojunction (53%)

10 results found

Journal ArticleDOI: 10.1002/SOLR.202100198
Ha L. Nguyen1Institutions (1)
01 Jul 2021-

10 Citations

Journal ArticleDOI: 10.1016/J.SURFIN.2021.101262
Zhu Yanchao1, Li En1, Zhao Hechuang1, Shengwei Shen1  +6 moreInstitutions (3)
Abstract: The narrow band-gap and long life-time of photo-generated charges endow CdS with much higher photocatalytic hydrogen evolution (PHE) activity over other photocatalysts. Thus, CdS based materials are considered to be most promising photocatalysts for PHE activity and stability. In this work, graphitic carbon nitride (GCN) is used as sacrifice agent to synthesize is nitrogen and carbon co-doped CdS nanoparticles with of uniform small size and higher specific surface area via hydrothermal reaction. Besides, co-doping of nitrogen and especially carbon leads to electron penetration to CdS results in tuned band structure of doped CdS with down-shifted conducting band and valance band positions. Moreover, the doped heteroatoms act as charge trapping centers that enhance charge separation within CdS particles endowing their photo-generated charges with longer life-time in compared with that of bare CdS. Benefited from non-metallic heteroatoms doping, obviously increased PHE activity and stability of CdS under visible light irradiation are achieved.

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Topics: Carbon nitride (59%), Graphitic carbon nitride (55%), Heteroatom (52%) ... read more

2 Citations

Journal ArticleDOI: 10.1016/J.JCIS.2021.09.168
Haizhao Zheng1, Zhiwei Chen2, Cheng Huang3, Linlin Gao1  +2 moreInstitutions (3)
Abstract: Designing high-efficiency heterojunction photocatalysts for water splitting is an intriguing prospect in energy conversion. Herein, we successfully fabricated a CdS/ZIF-8 heterojunction system through a facile wet-chemically method, in which ZIF-8 nanoparticles were in-situ adhered on hollow CdS nanotubes. Due to the well-matched band structure and intimate interface contact in CdS/ZIF-8 hybrid structure, the interfacial charge separation in the established system was tremendously boosted. As a consequence, the established CdS/ZIF-8 heterojunction exhibited the optimal photocatalytic hydrogen production performance (2.10 mmol·g−1 L−1), which was 35 times higher than pristine CdS (0.06 mmol·g−1·L−1). We believe this strategy will endow new insights for the development of novel photocatalysts.

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Topics: Heterojunction (51%), Water splitting (51%)

Journal ArticleDOI: 10.1016/J.JCIS.2021.07.052
Nuray Celebi1, Kouroush Salimi1Institutions (1)
Abstract: Herein, carbon-incorporated yolk-shell ZnO@C-CeO2 ternary heterostructures are employed as visible light responsive photocatalyst for highly efficient photoelectrochemical (PEC) water splitting. Compared to conventional ZnO/CeO2 semiconductors, introduction of a thin PDA shell layer assures the generation of a conductive N-doped graphitic carbon layer after a calcination post-treatment with mesoporous hollow morphologies. The evaluation of PEC water splitting performance of ZnO@C-CeO2 photoanodes reveals the maximum photocurrent density as 7.43 mA/cm2 at 1.18 V RHE under light whereas almost no response is recorded at dark. These superior PEC H2 evolution performance strongly implies efficient charge separation, facilitated charge transfer between photoanode and electrolyte interface as well as within the semiconductor bulk by means of rapid electron transfer ability of N-doped graphitic carbon layer and prolong life time of light inside yolk-shell structure. Furthermore, considerable depression in PL intensity of ZnO@C-CeO2 photoanodes compared to ZnO clearly reveals a higher photon absorption due to the reflection of light in hollow region and increase in electron hole separation efficiency. Moreover, plausible Z-scheme charge transfer mechanism using ZnO@C-CeO2 photoanodes under visible light illumination is verified using radical trapping experiments and X-ray photoelectron spectroscopy (XPS) methods, suggesting new generation of heterostructures for sufficient conversion of sunlight to H2 fuels.

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Topics: Water splitting (54%), Heterojunction (51%), Visible spectrum (51%) ... read more

Journal ArticleDOI: 10.1016/J.CEJ.2021.132595
Xu Li1, Yanli Zhang1, Qingping Xin1, Xiaoli Ding1  +5 moreInstitutions (1)
Abstract: Membrane absorption is a convenient and efficient flue SO2 capture technology. In this study, NH2-MIL-125 filled mixed matrix membrane contactor (MMMC) is constructed by Non-solvent Induced Phase Separation (NIPS) method. The functional groups and metal active sites on the surface of NH2-MIL-125(Ti) exhibit high affinity for SO2. The microporous structure of NH2-MIL-125(Ti) provides storage for adsorbed SO2, which is conducive to the formation of SO2 enrichment zone in the membrane. The membrane morphology, wetting resistance, and light responsiveness et al of MMMC have been tested. The combination of NH2-MIL-125(Ti) adsorption and membrane absorption process effectively promotes the transfer of gas molecules in the membrane pores. The SO2 absorption flux of MMMC filled by NH2-MIL-125(Ti) has a significant increment, reaching 8.81 × 10−4 mol·m−2·s−1 and 9.77 × 10−4 mol·m−2·s−1 under non-light and visible light conditions respectively, which is comparability with results in literature. The membrane phase mass transfer coefficient calculated by Wilson model is 149.6 s·m−1, which shows the low resistance in membrane. The SO2 absorption flux keep stable after 4 cycles of tests. The membrane contactor coupled with function fillers enhances the SO2 capture ability and further promotes the enrichment of SO2, which has favorable development foreground.

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Topics: Membrane (56%), Absorption (chemistry) (53%), Adsorption (52%) ... read more


76 results found

Journal ArticleDOI: 10.1038/NMAT2317
Xinchen Wang1, Kazuhiko Maeda2, Arne Thomas1, Kazuhiro Takanabe2  +4 moreInstitutions (2)
01 Jan 2009-Nature Materials
Abstract: The production of hydrogen from water using a catalyst and solar energy is an ideal future energy source, independent of fossil reserves. For an economical use of water and solar energy, catalysts that are sufficiently efficient, stable, inexpensive and capable of harvesting light are required. Here, we show that an abundant material, polymeric carbon nitride, can produce hydrogen from water under visible-light irradiation in the presence of a sacrificial donor. Contrary to other conducting polymer semiconductors, carbon nitride is chemically and thermally stable and does not rely on complicated device manufacturing. The results represent an important first step towards photosynthesis in general where artificial conjugated polymer semiconductors can be used as energy transducers.

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Topics: Energy source (59%), Photocatalytic water splitting (56%), Hydrogen production (56%) ... read more

7,884 Citations

Journal ArticleDOI: 10.1002/ADFM.201303214
Roland Marschall1Institutions (1)
Abstract: The formation of semiconductor composites comprising multicomponent or multiphase heterojunctions is a very effective strategy to design highly active photocatalyst systems. This review summarizes the recent strategies to develop such composites, and highlights the most recent developments in the fi eld. After a general introduction into the different strategies to improve photocatalytic activity through formation of heterojunctions, the three different types of heterojunctions are introduced in detail, followed by a historical introduction to semiconductor heterojunction systems and a thorough literature overview. Special chapters describe the highly-investigated carbon nitride heterojunctions as well as very recent developments in terms of multiphase heterojunction formation, including the latest insights into the anatase-rutile system. When carefully designed, semiconductor composites comprising two or three different materials or phases very effectively facilitate charge separation and charge carrier transfer, substantially improving photocatalytic and photoelectrochemical effi ciency.

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1,010 Citations

Journal ArticleDOI: 10.1039/C8CS00542G
Abstract: Overall water splitting based on particulate photocatalysts is an easily constructed and cost-effective technology for the conversion of abundant solar energy into clean and renewable hydrogen energy on a large scale. This promising technology can be achieved in a one-step excitation system using a single photocatalyst or via a Z-scheme process based on a pair of photocatalysts. Ideally, such photocatalysis will proceed with charge separation and transport unaffected by recombination and trapping, and surface catalytic processes will not involve undesirable reactions. This review summarizes the basics of overall water splitting via both one-step excitation and Z-scheme processes, with a focus on standard methods of determining photocatalytic performance. Various surface engineering strategies applied to photocatalysts, such as cocatalyst loading, surface morphology control, surface modification and surface phase junctions, have been developed to allow efficient one-step excitation overall water splitting. In addition, numerous visible-light-responsive photocatalysts have been successfully utilized as H2-evolution or O2-evolution photocatalysts in Z-scheme overall water splitting. Prototype particulate immobilization systems with photocatalytic performances comparable to or drastically higher than those of particle suspension systems suggest the exciting possibility of the large-scale production of low-cost renewable solar hydrogen.

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Topics: Water splitting (57%), Solar energy (50%)

825 Citations

Open accessJournal ArticleDOI: 10.1039/C7CS00122C
Ivo Stassen1, Nicholas C. Burtch2, A. Alec Talin2, Paolo Falcaro3  +3 moreInstitutions (4)
Abstract: Metal-organic frameworks (MOFs) are typically highlighted for their potential application in gas storage, separations and catalysis. In contrast, the unique prospects these porous and crystalline materials offer for application in electronic devices, although actively developed, are often underexposed. This review highlights the research aimed at the implementation of MOFs as an integral part of solid-state microelectronics. Manufacturing these devices will critically depend on the compatibility of MOFs with existing fabrication protocols and predominant standards. Therefore, it is important to focus in parallel on a fundamental understanding of the distinguishing properties of MOFs and eliminating fabrication-related obstacles for integration. The latter implies a shift from the microcrystalline powder synthesis in chemistry labs, towards film deposition and processing in a cleanroom environment. Both the fundamental and applied aspects of this two-pronged approach are discussed. Critical directions for future research are proposed in an updated high-level roadmap to stimulate the next steps towards MOF-based microelectronics within the community.

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699 Citations

Journal ArticleDOI: 10.1039/SA9700700069
Ivo Stassen1, Nicholas C. Burtch2, A. Alec Talin2, Paolo Falcaro3  +3 moreInstitutions (4)
01 Jan 1970-

612 Citations