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1.
Jing Zhang Jingjie Wu Hua Guo Weibing Chen Jiangtan Yuan Ulises Martinez Gautam Gupta Aditya Mohite Pulickel M. Ajayan Jun Lou 《Advanced materials (Deerfield Beach, Fla.)》2017,29(42)
Here, the hydrogen evolution reaction (HER) activities at the edge and basal‐plane sites of monolayer molybdenum disulfide (MoS2) synthesized by chemical vapor deposition (CVD) are studied using a local probe method enabled by selected‐area lithography. Reaction windows are opened by e‐beam lithography at sites of interest on poly(methyl methacrylate) (PMMA)‐covered monolayer MoS2 triangles. The HER properties of MoS2 edge sites are obtained by subtraction of the activity of the basal‐plane sites from results containing both basal‐plane and edge sites. The catalytic performances in terms of turnover frequencies (TOFs) are calculated based on the estimated number of active sites on the selected areas. The TOFs follow a descending order of 3.8 ± 1.6, 1.6 ± 1.2, 0.008 ± 0.002, and 1.9 ± 0.8 × 10?4 s?1, found for 1T′‐, 2H‐MoS2 edges, and 1T′‐, 2H‐MoS2 basal planes, respectively. Edge sites of both 2H‐ and 1T′‐MoS2 are proved to have comparable activities to platinum (≈1–10 s?1). When fitted into the HER volcano plot, the MoS2 active sites follow a trend distinct from conventional metals, implying a possible difference in the reaction mechanism between transition‐metal dichalcogenides (TMDs) and metal catalysts. 相似文献
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Chuanyong Jian Qian Cai Wenting Hong Jing Li Wei Liu 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(13)
Molybdenum diselenide (MoSe2) is widely considered as one of the most promising catalysts for the hydrogen evolution reaction (HER). However, the absence of active sites and poor conductivity of MoSe2 severely restrict its HER performance. By introducing a layer of MoO2 on Mo foil, MoSe2/MoO2 hybrid nanosheets with an abundant edge and high electrical conductivity can be synthesized on the surface of Mo foil. Metallic MoO2 can improve the charge transport efficiency of MoSe2/MoO2, thereby enhancing the overall HER performance. MoSe2/MoO2 exhibits fast hydrogen evolution kinetics with a small overpotential of 142 mV versus RHE at a current density of 10 mA cm?2 and Tafel slope of 48.9 mV dec?1. 相似文献
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Kan Zhang Bingjun Jin Yujie Gao Shengli Zhang Hyunjung Shin Haibo Zeng Jong Hyeok Park 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(8)
1T‐phase molybdenum disulfide (1T‐MoS2) exhibits superior hydrogen evolution reaction (HER) over 2H‐phase MoS2 (2H‐MoS2). However, its thermodynamic instability is the main drawback impeding its practical application. In this work, a stable 1T‐MoS2 monolayer formed at edge‐aligned 2H‐MoS2 and a reduced graphene oxide heterointerface (EA‐2H/1T/RGO) using a precursor‐in‐solvent synthesis strategy are reported. Theoretical prediction indicates that the edge‐aligned layer stacking can induce heterointerfacial charge transfer, which results in a phase transition of the interfacial monolayer from 2H to 1T that realizes thermodynamic stability based on the adhesion energy between MoS2 and graphene. As an electrocatalyst for HER, EA‐2H/1T/RGO displays an onset potential of ?103 mV versus RHE, a Tafel slope of 46 mV dec?1 and 10 h stability in acidic electrolyte. The unexpected activity of EA‐2H/1T/RGO beyond 1T‐MoS2 is due to an inherent defect caused by the gliding of S atoms during the phase transition from 2H to 1T, leading the Gibbs free energy of hydrogen adsorption (ΔGH*) to decrease from 0.13 to 0.07 eV, which is closest to the ideal value (0.06 eV) of 2H‐MoS2. The presented work provides fundamental insights into the impressive electrochemical properties of HER and opens new avenues for phase transitions at 2D/2D hybrid interfaces. 相似文献
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Ke Guo Jinyu Zheng Jianchun Bao Yafei Li Dongdong Xu 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(26):2208077
Surface modification of electrocatalysts to obtain new or improved electrocatalytic performance is currently the main strategy for designing advanced nanocatalysts. In this work, highly dispersed amorphous molybdenum trisulfide-anchored Platinum nanodendrites (denoted as Pt-a-MoS3 NDs) are developed as efficient hydrogen evolution electrocatalysts. The formation mechanism of spontaneous in situ polymerization MoS42− into a-MoS3 on Pt surface is discussed in detail. It is verified that the highly dispersed a-MoS3 enhances the electrocatalytic activity of Pt catalysts under both acidic and alkaline conditions. The potentials at the current density of 10 mA cm−2 (η10) in 0.5 m sulfuric acid (H2SO4) and 1 m potassium hydroxide (KOH) electrolyte are −11.5 and −16.3 mV, respectively, which is significantly lower than that of commercial Pt/C (−20.2 mV and −30.7 mV). This study demonstrates that such high activity benefits from the interface between highly dispersed a-MoS3 and Pt sites, which act as the preferred adsorption sites for the efficient conversion of hydrion (H+) to hydrogen (H2). Additionally, the anchoring of highly dispersed clusters to Pt substrate greatly enhances the corresponding electrocatalytic stability. 相似文献
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Wencui Zhang Xiaobin Liao Xuelei Pan Mengyu Yan Yanxi Li Xiaocong Tian Yan Zhao Lin Xu Liqiang Mai 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(31)
In the hydrogen evolution reaction (HER), energy‐level matching is a prerequisite for excellent electrocatalytic activity. Conventional strategies such as chemical doping and the incorporation of defects underscore the complicated process of controlling the doping species and the defect concentration, which obstructs the understanding of the function of band structure in HER catalysis. Accordingly, 2H‐MoS2 and 1T‐MoS2 are used to create electrocatalytic nanodevices to address the function of band structure in HER catalysis. Interestingly, it is found that the 2H‐MoS2 with modulated Fermi level under the application of a vertical electric field exhibits excellent electrocatalytic activity (as evidenced by an overpotential of 74 mV at 10 mA cm?2 and a Tafel slope of 99 mV per decade), which is superior to 1T‐MoS2. This unexpected excellent HER performance is ascribed to the fact that electrons are injected into the conduction band under the condition of back‐gate voltage, which leads to the increased Fermi level of 2H‐MoS2 and a shorter Debye screen length. Hence, the required energy to drive electrons from the electrocatalyst surface to reactant will decrease, which activates the 2H‐MoS2 thermodynamically. 相似文献
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Sayyar Ali Shah Xiaoping Shen Minghua Xie Guoxing Zhu Zhenyuan Ji Hongbo Zhou Keqiang Xu Xiaoyang Yue Aihua Yuan Jun Zhu Yao Chen 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(9)
Developing cheap, abundant, and easily available electrocatalysts to drive the hydrogen evolution reaction (HER) at small overpotentials is an urgent demand of hydrogen production from water splitting. Molybdenum disulfide (MoS2) based composites have emerged as competitive electrocatalysts for HER in recent years. Herein, nickel@nitrogen‐doped carbon@MoS2 nanosheets (Ni@NC@MoS2) hybrid sub‐microspheres are presented as HER catalyst. MoS2 nanosheets with expanded interlayer spacings are vertically grown on nickel@nitrogen‐doped carbon (Ni@NC) substrate to form Ni@NC@MoS2 hierarchical sub‐microspheres by a simple hydrothermal process. The formed Ni@NC@MoS2 composites display excellent electrocatalytic activity for HER with an onset overpotential of 18 mV, a low overpotential of 82 mV at 10 mA cm?2, a small Tafel slope of 47.5 mV dec?1, and high durability in 0.5 H2SO4 solution. The outstanding HER performance of the Ni@NC@MoS2 catalyst can be ascribed to the synergistic effect of dense catalytic sites on MoS2 nanosheets with exposed edges and expanded interlayer spacings, and the rapid electron transfer from Ni@NC substrate to MoS2 nanosheets. The excellent Ni@NC@MoS2 electrocatalyst promises potential application in practical hydrogen production, and the strategy reported here can also be extended to grow MoS2 on other nitrogen‐doped carbon encapsulated metal species for various applications. 相似文献
8.
Yangyang Feng Ting Zhang Jiahui Zhang Hao Fan Cheng He Jiangxuan Song 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(33)
Metallic phase (1T) MoS2 has been regarded as an appealing material for hydrogen evolution reaction. In this work, a novel interface‐induced strategy is reported to achieve stable and high‐percentage 1T MoS2 through highly active 1T‐MoS2/CoS2 hetero‐nanostructure. Herein, a large number of heterointerfaces can be obtained by interlinked 1T‐MoS2 and CoS2 nanosheets in situ grown from the molybdate cobalt oxide nanorod under moderate conditions. Owing to the strong interaction between MoS2 and CoS2, high‐percentage of metallic‐phase (1T) MoS2 of 76.6% can be achieved, leading to high electroconductivity and abundant active sites compared to 2H MoS2. Furthermore, the interlinked MoS2 and CoS2 nanosheets can effectively disperse the nanosheets so as to enlarge the exposed active surface area. The near zero free energy of hydrogen adsorption at the heterointerface can also be achieved, indicating the fast kinetics and excellent catalytic activity induced by heterojunction. Therefore, when applied in hydrogen evolution reaction (HER), 1T‐MoS2/CoS2 heterostructure delivers low overpotential of 71 and 26 mV at the current density of 10 mA cm?2 with low Tafel slops of 60 and 43 mV dec?1, respectively in alkaline and acidic conditions. 相似文献
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Highly Efficient Photocatalytic Hydrogen Evolution by ReS2 via a Two‐Electron Catalytic Reaction
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Qin Zhang Wenjie Wang Jiaqian Zhang Xiaohui Zhu Qiqi Zhang Yujing Zhang Zemian Ren Shuaishuai Song Jinming Wang Zihao Ying Rui Wang Xiaohui Qiu Tianyou Peng Lei Fu 《Advanced materials (Deerfield Beach, Fla.)》2018,30(23)
Highly efficient photocatalytic hydrogen evolution (PHE) is highly desirable for addressing the global energy crisis and environmental problems. Although much attention has been given to electron–hole separation, ridding photocatalysts of poor efficiency remains challenging. Here, a two‐electron catalytic reaction is developed by utilizing the distinct trion behavior of ReS2 and the efficient reduction of two H+ (2H+ + 2e? → H2) is realized. Due to the monolayer‐like structure of the catalyst, the free electrons in ReS2 can be captured by the tightly bound excitons to form trions consisting of two electrons and one hole. These trions can migrate to the surface and participate in the two‐electron reaction at the abundant active sites. As expected, such a two‐electron catalytic reaction endows ReS2 with a PHE rate of 13 mmol g?1 h?1 under visible light irradiation. Meanwhile, this reaction allows the typically poor PHE efficiency of pure transition metal dichalcogenides to be overcome. The proposed two‐electron catalytic reaction provides a new approach to the design of photocatalysts for PHE. 相似文献
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Structurally Deformed MoS2 for Electrochemically Stable,Thermally Resistant,and Highly Efficient Hydrogen Evolution Reaction
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Yen‐Chang Chen Ang‐Yu Lu Ping Lu Xiulin Yang Chang‐Ming Jiang Marina Mariano Bryan Kaehr Oliver Lin André Taylor Ian D. Sharp Lain‐Jong Li Stanley S. Chou Vincent Tung 《Advanced materials (Deerfield Beach, Fla.)》2017,29(44)
The emerging molybdenum disulfide (MoS2) offers intriguing possibilities for realizing a transformative new catalyst for driving the hydrogen evolution reaction (HER). However, the trade‐off between catalytic activity and long‐term stability represents a formidable challenge and has not been extensively addressed. This study reports that metastable and temperature‐sensitive chemically exfoliated MoS2 (ce‐MoS2) can be made into electrochemically stable (5000 cycles), and thermally robust (300 °C) while maintaining synthetic scalability and excellent catalytic activity through physical‐transformation into 3D structurally deformed nanostructures. The dimensional transition enabled by a high throughput electrohydrodynamic process provides highly accessible, and electrochemically active surface area and facilitates efficient transport across various interfaces. Meanwhile, the hierarchically strained morphology is found to improve electronic coupling between active sites and current collecting substrates without the need for selective engineering the electronically heterogeneous interfaces. Specifically, the synergistic combination of high strain load stemmed from capillarity‐induced‐self‐crumpling and sulfur (S) vacancies intrinsic to chemical exfoliation enables simultaneous modulation of active site density and intrinsic HER activity regardless of continuous operation or elevated temperature. These results provide new insights into how catalytic activity, electrochemical‐, and thermal stability can be concurrently enhanced through the physical transformation that is reminiscent of nature, in which properties of biological materials emerge from evolved dimensional transitions. 相似文献
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Hyeong‐U Kim Vinit Kanade Mansu Kim Ki Seok Kim Byeong‐Seon An Hyunho Seok Hocheon Yoo Lindsay E. Chaney Seung‐Il Kim Cheol‐Woong Yang Geun Yong Yeom Dongmok Whang Jae‐Hyun Lee Taesung Kim 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(6)
The metallic 1T phase of WS2 (1T‐WS2), which boosts the charge transfer between the electron source and active edge sites, can be used as an efficient electrocatalyst for the hydrogen evolution reaction (HER). As the semiconductor 2H phase of WS2 (2H‐WS2) is inherently stable, methods for synthesizing 1T‐WS2 are limited and complicated. Herein, a uniform wafer‐scale 1T‐WS2 film is prepared using a plasma‐enhanced chemical vapor deposition (PE‐CVD) system. The growth temperature is maintained at 150 °C enabling the direct synthesis of 1T‐WS2 films on both rigid dielectric and flexible polymer substrates. Both the crystallinity and number of layers of the as‐grown 1T‐WS2 are verified by various spectroscopic and microscopic analyses. A distorted 1T structure with a 2a0 × a0 superlattice is observed using scanning transmission electron microscopy. An electrochemical analysis of the 1T‐WS2 film demonstrates its similar catalytic activity and high durability as compared to those of previously reported untreated and planar 1T‐WS2 films synthesized with CVD and hydrothermal methods. The 1T‐WS2 does not transform to stable 2H‐WS2, even after a 700 h exposure to harsh catalytic conditions and 1000 cycles of HERs. This synthetic strategy can provide a facile method to synthesize uniform 1T‐phase 2D materials for electrocatalysis applications. 相似文献
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Zhuoping Wang Kai Chi Shengxiong Yang Junwu Xiao Fei Xiao Xiaoxu Zhao Shuai Wang 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(28):2301403
Developing efficient and stable electrocatalysts for hydrogen evolution reaction (HER) over a wide pH range and industrial large-scale hydrogen production is critical and challenging. Here, a tailoring strategy is developed to fabricate an outstanding HER catalyst in both acidic and alkaline electrolytes containing high-density atomically dispersed Ru sites anchored in the CoP nanoparticles supported on carbon spheres (NC@RuSA-CoP). The obtained NC@RuSA-CoP catalyst exhibits excellent HER performance with overpotentials of only 15 and 13 mV at 10 mA cm−2 in 1 m KOH and 0.5 m H2SO4, respectively. The experimental results and theoretical calculations indicate that the strong interaction between the Ru site and the CoP can effectively optimize the electronic structure of Ru sites to reduce the hydrogen binding energy and the water dissociation energy barrier. The constructed alkaline anion exchange membrane water electrolyze (AAEMWE) demonstrates remarkable durability and an industrial-level current density of 1560 mA cm−2 at 1.8 V. This strategy provides a new perspective on the design of Ru-based electrocatalysts with suitable intermediate adsorption strengths and paves the way for the development of highly active electrocatalysts for industrial-scale hydrogen production. 相似文献
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Self‐Templated Fabrication of MoNi4/MoO3‐x Nanorod Arrays with Dual Active Components for Highly Efficient Hydrogen Evolution
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Yu‐Yun Chen Yun Zhang Xing Zhang Tang Tang Hao Luo Shuai Niu Zhi‐Hui Dai Li‐Jun Wan Jin‐Song Hu 《Advanced materials (Deerfield Beach, Fla.)》2017,29(39)
A binder‐free efficient MoNi4/MoO3‐x nanorod array electrode with 3D open structure is developed by using Ni foam as both scaffold and Ni source to form NiMoO4 precursor, followed by subsequent annealing in a reduction atmosphere. It is discovered that the self‐templated conversion of NiMoO4 into MoNi4 nanocrystals and MoO3‐x as dual active components dramatically boosts the hydrogen evolution reaction (HER) performance. Benefiting from high intrinsic activity, high electrochemical surface area, 3D open network, and improved electron transport, the resulting MoNi4/MoO3‐x electrode exhibits a remarkable HER activity with extremely low overpotentials of 17 mV at 10 mA cm?2 and 114 mV at 500 mA cm?2, as well as a superior durability in alkaline medium. The water–alkali electrolyzer using MoNi4/MoO3‐x as cathode achieves stable overall water splitting with a small cell voltage of 1.6 V at 30 mA cm ? 2. These findings may inspire the exploration of cost‐effective and efficient electrodes by in situ integrating multiple highly active components on 3D platform with open conductive network for practical hydrogen production. 相似文献
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Qian Liu Ziqian Xue Baoming Jia Qinglin Liu Kang Liu Yiyang Lin Min Liu Yinle Li Guangqin Li 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(32)
Hierarchical nanostructures with tailored component and architectures are attractive for energy‐related applications. Here, the delicate design and construction of hierarchical MoS2/MoP (H‐MoS2/MoP) nanorods for the hydrogen evolution reaction (HER) are demonstrated. This multiscale design rationally combines the compositional and structural advantages of MoS2/MoP heterojunction into a hierarchical architecture, which can modulate electronic structure of S, remarkably facilitating the electrocatalytic HER. Benefitting from their unique architecture and electronic structure, the H‐MoS2/MoP nanorods exhibit excellent performance for HER with ultralow overpotential of 92 mV at current density of 10 mA cm?2 in 1 m KOH and high stability. This work not only provides an efficient approach to constructing hierarchical heterojunctions, but also a multiscale strategy for all‐round regulation of the electronic structure and hierarchical morphology of nanomaterials for energy‐related applications. 相似文献
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High‐Sulfur‐Vacancy Amorphous Molybdenum Sulfide as a High Current Electrocatalyst in Hydrogen Evolution
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Ang‐Yu Lu Xiulin Yang Chien‐Chih Tseng Shixiong Min Shi‐Hsin Lin Chang‐Lung Hsu Henan Li Hicham Idriss Jer‐Lai Kuo Kuo‐Wei Huang Lain‐Jong Li 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(40):5530-5537
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Directional Construction of Vertical Nitrogen‐Doped 1T‐2H MoSe2/Graphene Shell/Core Nanoflake Arrays for Efficient Hydrogen Evolution Reaction
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Shengjue Deng Yu Zhong Yinxiang Zeng Yadong Wang Zhujun Yao Fan Yang Shiwei Lin Xiuli Wang Xihong Lu Xinhui Xia Jiangping Tu 《Advanced materials (Deerfield Beach, Fla.)》2017,29(21)
The low utilization of active sites and sluggish reaction kinetics of MoSe2 severely impede its commercial application as electrocatalyst for hydrogen evolution reaction (HER). To address these two issues, the first example of introducing 1T MoSe2 and N dopant into vertical 2H MoSe2/graphene shell/core nanoflake arrays that remarkably boost their HER activity is herein described. By means of the improved conductivity, rich catalytic active sites and highly accessible surface area as a result of the introduction of 1T MoSe2 and N doping as well as the unique structural features, the N‐doped 1T‐2H MoSe2/graphene (N‐MoSe2/VG) shell/core nanoflake arrays show substantially enhanced HER activity. Remarkably, the N‐MoSe2/VG nanoflakes exhibit a relatively low onset potential of 45 mV and overpotential of 98 mV (vs RHE) at 10 mA cm?2 with excellent long‐term stability (no decay after 20 000 cycles), outperforming most of the recently reported Mo‐based electrocatalysts. The success of improving the electrochemical performance via the introduction of 1T phase and N dopant offers new opportunities in the development of high‐performance MoSe2‐based electrodes for other energy‐related applications. 相似文献