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71.
Yi Lu Hao Zhang Yida Wang Xiaorong Zhu Weiping Xiao Haolan Xu Gaoran Li Yafei Li Deqi Fan Haibo Zeng Zupeng Chen Xiaofei Yang 《Advanced functional materials》2023,33(21):2215061
The rational design of economic and high-performance electrocatalytic water-splitting systems is of great significance for energy and environmental sustainability. Developing a sustainable energy conversion-assisted electrocatalytic process provides a promising novel approach to effectively boost its performance. Herein, a self-sustained water-splitting system originated from the heterostructure of perovskite oxide with 2D Ti3C2Tx MXene on Ni foam (La1-xSrxCoO3/Ti3C2Tx MXene/Ni) that shows high activity for solar-powered water evaporation and simultaneous electrocatalytic water splitting is presented. The all-in-one interfacial electrocatalyst exhibits highly improved oxygen evolution reaction (OER) performance with a low overpotential of 279 mV at 10 mA cm−2 and a small Tafel slope of 74.3 mV dec−1, superior to previously reported perovskite oxide-based electrocatalysts. Density functional theory calculations reveal that the integration of La0.9Sr0.1CoO3 with Ti3C2Tx MXene can lower the energy barrier for the electron transfer and decrease the OER overpotential, while COMSOL simulations unveil that interfacial solar evaporation could induce OH− enrichment near the catalyst surfaces and enhance the convection flow above the catalysts to remove the generated gas, remarkably accelerating the kinetics of electrocatalytic water splitting. 相似文献
72.
Xin Ding Run Jiang Jialin Wu Minghui Xing Zelong Qiao Xiaofei Zeng Shitao Wang Dapeng Cao 《Advanced functional materials》2023,33(47):2306786
Developing low-cost and high-efficient bifunctional catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is greatly significant for water electrolysis. Here, Ni3N-CeO2/NF heterostructure is synthesized on the nickel foam, and it exhibits excellent HER and OER performance. As a result, the water electrolyzer based on Ni3N-CeO2/NF bifunctional catalyst only needs 1.515 V@10 mA cm−2, significantly better than that of Pt/C||IrO2 catalysts. In situ characterizations unveil that CeO2 plays completely different roles in HER and OER processes. In situ infrared spectroscopy and density functional theory calculations indicate that the introduction of CeO2 can optimizes the structure of interface water, and the synergistic effect of Ni3N and CeO2 improve the HER activity significantly, while the in situ Raman spectra reveal that CeO2 accelerates the reconstruction of OV (oxygen vacancy)-rich NiOOH for boosting OER. This study clearly unlocks the different catalytic mechanisms of CeO2 for boosting the HER and OER activity of Ni3N for water splitting, which provides the useful guidance for designing the high-performance bifunctional catalysts for water splitting. 相似文献
73.
为指导某600 mm口径的双曲面反射镜的加工,设计了Ronchi光栅检测系统。针对系统检测过程中存在的杂光现象,分析产生该现象的原因,并提出相应的解决方案。结果表明,在光线两次经过光栅的光路结构中,分光棱镜的剩余反射率大于5%时,像面处暗条纹的照度增大27倍,条纹明暗对比度下降,难以分辨;随着光栅剩余反射增加,条纹中心产生亮斑现象,条纹无法分辨。条纹面正对分光镜的亮斑区域的背景照度增加40多倍,玻璃面正对分光镜的亮斑区域的背景照度增加80多倍。通过优化系统结构,对分光镜与光栅进行替换与表面处理,有效解决了杂光问题,提高了像面条纹对比度。 相似文献
74.
Hengfei Gu Fei Zhang Shinjae Hwang Anders B. Laursen Xin Liu So Yeon Park Mengjin Yang Rosemary C. Bramante Hussein Hijazi Leila Kasaei Leonard C. Feldman Yao-Wen Yeh Philip E. Batson Bryon W. Larson Mengjun Li Yifei Li Keenan Wyatt James L. Young Krishani Teeluck Kai Zhu Eric Garfunkel G. Charles Dismukes 《Advanced functional materials》2023,33(25):2301196
The rapidly increasing solar conversion efficiency (PCE) of hybrid organic–inorganic perovskite (HOIP) thin-film semiconductors has triggered interest in their use for direct solar-driven water splitting to produce hydrogen. However, application of these low-cost, electronic-structure-tunable HOIP tandem photoabsorbers has been hindered by the instability of the photovoltaic-catalyst-electrolyte (PV+E) interfaces. Here, photolytic water splitting is demonstrated using an integrated configuration consisting of an HOIP/n+silicon single junction photoabsorber and a platinum (Pt) thin film catalyst. An extended electrochemical (EC) lifetime in alkaline media is achieved using titanium nitride on both sides of the Si support to eliminate formation of insulating silicon oxide, and as an effective diffusion barrier to allow high-temperature annealing of the catalyst/TiO2-protected-n+silicon interface necessary to retard electrolytic corrosion. Halide composition is examined in the (FA1-xCsx)PbI3 system with a bandgap suitable for tandem operation. A fill factor of 72.5% is achieved using a Spiro-OMeTAD-hole-transport-layer (HTL)-based HOIP/n+Si solar cell, and a high photocurrent density of −15.9 mA cm−2 (at 0 V vs reversible hydrogen electrode) is attained for the HOIP/n+Si/Pt photocathode in 1 m NaOH under simulated 1-sun illumination. While this thin-film design creates stable interfaces, the intrinsic photo- and electro-degradation of the HOIP photoabsorber remains the main obstacle for future HOIP/Si tandem PEC devices. 相似文献
75.
Thanh Hai Nguyen Phan Khanh Linh Tran Van An Dinh Duy Thanh Tran Nam Hoon Kim Joong Hee Lee 《Advanced functional materials》2023,33(7):2210101
Development of multifunctional electrocatalysts with high efficiency and stability is of great interest in recent energy conversion technologies. Herein, a novel heteroelectrocatalyst of molecular iron complex (FeMC)-carbide MXene (Mo2TiC2Tx) uniformly embedded in a 3D graphene-based hierarchical network (GrH) is rationally designed. The coexistence of FeMC and MXene with their unique interactions triggers optimum electronic properties, rich multiple active sites, and favorite free adsorption energy for excellent trifunctional catalytic activities. Meanwhile, the highly porous GrH effectively promotes a multichannel architecture for charge transfer and gas/ion diffusion to improve stability. Therefore, the FeMC–MXene/GrH results in superb performances towards oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) in alkaline medium. The practical tests indicate that Zn/Al–air batteries derived from FeMC–MXene/GrH cathodic electrodes produce high power densities of 165.6 and 172.7 mW cm−2, respectively. Impressively, the liquid-state Zn–air battery delivers excellent cycling stability of over 1100 h. In addition, the alkaline water electrolyzer induces a low cell voltage of 1.55 V at 10 mA cm−2 and 1.86 V at 0.4 A cm−2 in 30 wt.% KOH at 80 °C, surpassing recent reports. The achievements suggest an exciting multifunctional electrocatalyst for electrochemical energy applications. 相似文献
76.
Yuki Akinaga Tokuhisa Kawawaki Hinano Kameko Yuki Yamazaki Kenji Yamazaki Yuhi Nakayasu Kosaku Kato Yuto Tanaka Adie Tri Hanindriyo Makito Takagi Tomomi Shimazaki Masanori Tachikawa Akira Yamakata Yuichi Negishi 《Advanced functional materials》2023,33(33):2303321
Single-atom (SA) catalysts exhibit high activity in various reactions because there are no inactive internal atoms. Accordingly, SA cocatalysts are also an active research fields regarding photocatalytic hydrogen (H2) evolution which can be generated by abundant water and sunlight. Herein, it is investigated whether 10 transition metal elements can work as an SA on graphitic carbon nitride (g-C3N4; i.e., gCN), a promising visible-light-driven photocatalyst. A method is established to prepare SA-loaded gCN at high loadings (weight of ≈3 wt.% for Cu, Ni, Pd, Pt, Rh, and Ru) by modulating the photoreduction power. Regarding Au and Ag, SAs are formed with difficulty without aggregation because of the low binding energy between gCN and the SA. An evaluation of the photocatalytic H2-evolution activity of the prepared metal SA-loaded gCN reveals that Pd, Pt, and Rh SA-loaded gCN exhibits relatively high H2-evolution efficiency per SA. Transient absorption spectroscopy and electrochemical measurements reveal the following: i) Pd SA-loaded gCN exhibits a particularly suitable electronic structure for proton adsorption and ii) therefore they exhibit the highest H2-evolution efficiency per SA than other metal SA-loaded gCN. Finally, the 8.6 times higher H2-evolution rate per active site of Pd SA is achieved than that of Pd-nanoparticles cocatalyst. 相似文献
77.
Yikun Su Weirui Yu Liming Liao Xinbo Xiong Huanwen Chen Lingzhi Hu Tongjia Lei Jinlai Zhao Dong Chen Wenjie Mai 《Advanced functional materials》2023,33(42):2303976
Photo-electrochemical (PEC) water splitting is a promising method for converting solar energy into clean energy, but the mechanism of improving PEC efficiency through the interfacial contact and defect strategy remains highly controversial. Herein, reduced graphene oxide (rGO) and oxygen vacancies are introduced into α-Fe2O3 nanorod (NR) arrays using a simple spin-coating method and acid treatment. The resultant oxygen vacancy–α-Fe2O3/rGO-integrated system exhibits a higher photocurrent, four times than the pristine α-Fe2O3. It is well evidenced that the electronic interface interaction between α-Fe2O3 and rGO is boosted with the oxygen vacancies, facilitating electron transfer from α-Fe2O3 to rGO. Moreover, the oxygen vacancies not only create interband states in α-Fe2O3 that can trap photogenerated holes and thus facilitate charge separation but significantly also strengthen the adsorption of oxidative intermediates and reduce the energy barrier of rate-determining step during oxygen evolution reaction (OER). This study demonstrates an rGO–oxygen vacancy synergistic interfacial contact and defect modification approach to design semiconducting photocatalysts for high-efficiency solar energy capture and conversion. The generated principle is expected to be extendable to another material system. 相似文献
78.
79.
Adaptive relay co-ordination using a busbar splitting approach for a system integrity protection scheme 下载免费PDF全文
Power system faults can often result in excessively high currents. If sustained for a long time, such high currents can damage system equipment. Thus, it is desirable to operate the relays in the minimum possible time. In this paper, a busbar splitting approach is used for adaptive relay setting and co-ordination purposes for a system integrity protection scheme (SIPS). Whenever a fault occurs, the busbar splitting scheme splits a bus to convert a loop into a radial structure. The splitting schemes are chosen such that the net fault current is also reduced. Busbar splitting eliminates the dependency upon minimum breakpoints set (MBPS) and reduces the relay operating time, thus making it adaptive. The proposed methodology is incorporated into the IEEE 14-bus and IEEE 30-bus systems with single and multiple fault conditions. The modeling and simulation carried out in ETAP, and the results of the proposed busbar splitting-based relay co-ordination are compared with the MBPS splitting-based relay co-ordination. 相似文献
80.
Bo‐Quan Li Shu‐Yuan Zhang Cheng Tang Xiaoyang Cui Qiang Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(25)
The construction of active sites with intrinsic oxygen evolution reaction (OER) is of great significance to overcome the limited efficiency of abundant sustainable energy devices such as fuel cells, rechargeable metal–air batteries, and in water splitting. Anionic regulation of electrocatalysts by modulating the electronic structure of active sites significantly promotes OER performance. To prove the concept, NiFeS electrocatalysts are fabricated with gradual variation of atomic ratio of S:O. With the rise of S content, the overpotential for water oxidation exhibits a volcano plot under anionic regulation. The optimized NiFeS‐2 electrocatalyst under anionic regulation possesses the lowest OER overpotential of 286 mV at 10 mA cm?2 and the fastest kinetics being 56.3 mV dec?1 to date. The anionic regulation methodology not only serves as an effective strategy to construct superb OER electrocatalysts, but also enlightens a new point of view for the in‐depth understanding of electrocatalysis at the electronic and atomic level. 相似文献