A facile two-step method for fabrication of plate-like WO3 photoanode under mild conditions

2014 ◽  
Vol 176 ◽  
pp. 185-197 ◽  
Author(s):  
Nan Wang ◽  
Jian Zhu ◽  
Xiaojia Zheng ◽  
Fengqiang Xiong ◽  
Baokun Huang ◽  
...  

Fabrication of photoelectrodes on a large-scale, with low-cost and high efficiency is a challenge for their practical application in photoelectrochemical (PEC) water splitting. In this work, a typical plate-like WO3 photoanode was fabricated with chemical etching of the as-prepared mixed tungsten–metal oxides (W–M–O, M = Cu, Zn or Al) by a reactive magnetron co-sputtering technique, which results in a greatly enhanced PEC performance for water oxidation in comparison with that obtained from a conventional magnetron sputtering method. The current approach is applicable for the fabrication of some other semiconductor photoelectrodes and is promising for the scaling up of applications for highly efficient solar energy conversion systems.

2021 ◽  
Author(s):  
Ru Cui ◽  
Jie Sheng ◽  
Bing-Bing Wu ◽  
Duo-Duo Hu ◽  
Hong-Qian Zheng ◽  
...  

A nickel-catalysed direct terminal monofluormethlyation between alkyl tosylates and a low-cost, industrial raw material bromofluoromethane has been developed. This transformation has demonstrated high efficiency, mild conditions, and good functional-group compatibility....


Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 926 ◽  
Author(s):  
Yury Kutin ◽  
Nicholas Cox ◽  
Wolfgang Lubitz ◽  
Alexander Schnegg ◽  
Olaf Rüdiger

Here we report an in situ electron paramagnetic resonance (EPR) study of a low-cost, high-stability cobalt oxide electrodeposited material (Co-Pi) that oxidizes water at neutral pH and low over-potential, representing a promising system for future large-scale water splitting applications. Using CW X-band EPR we can follow the film formation from a Co(NO3)2 solution in phosphate buffer and quantify Co uptake into the catalytic film. As deposited, the film shows predominantly a Co(II) EPR signal, which converts into a Co(IV) signal as the electrode potential is increased. A purpose-built spectroelectrochemical cell allowed us to quantify the extent of Co(II) to Co(IV) conversion as a function of potential bias under operating conditions. Consistent with its role as an intermediate, Co(IV) is formed at potentials commensurate with electrocatalytic O2 evolution (+1.2 V, vs. SHE). The EPR resonance position of the Co(IV) species shifts to higher fields as the potential is increased above 1.2 V. Such a shift of the Co(IV) signal may be assigned to changes in the local Co structure, displaying a more distorted ligand field or more ligand radical character, suggesting it is this subset of sites that represents the catalytically ‘active’ component. The described spectroelectrochemical approach provides new information on catalyst function and reaction pathways of water oxidation.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Xing Xing ◽  
Zaiqin Man ◽  
Jie Bian ◽  
Yadong Yin ◽  
Weihua Zhang ◽  
...  

AbstractFast, low-cost, reliable, and multi-component nanopatterning techniques for functional colloidal nanoparticles have been dreamed about by scientists and engineers for decades. Although countless efforts have been made, it is still a daunting challenge to organize different nanocomponents into a predefined structure with nanometer precision over the millimeter and even larger scale. To meet the challenge, we report a nanoprinting technique that can print various functional colloidal nanoparticles into arbitrarily defined patterns with a 200 nm (or smaller) pitch (>125,000 DPI), 30 nm (or larger) pixel size/linewidth, 10 nm position accuracy and 50 nm overlay precision. The nanopatterning technique combines dielectrophoretic enrichment and deep surface-energy modulation and therefore features high efficiency and robustness. It can form nanostructures over the millimeter-scale by simply spinning, brushing or dip coating colloidal nanoink onto a substrate with minimum error (error ratio < 2 × 10−6). This technique provides a powerful yet simple construction tool for large-scale positioning and integration of multiple functional nanoparticles toward next-generation optoelectronic and biomedical devices.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Chouki Balakishan ◽  
N. Sandeep ◽  
M. V. Aware

In many photovoltaic (PV) energy conversion systems, nonisolated DC-DC converters with high voltage gain are desired. The PV exhibits a nonlinear power characteristic which greatly depends on the environmental conditions. Hence in order to draw maximum available power various algorithms are used with PV voltage/current or both as an input for the maximum power point tracking (MPPT) controller. In this paper, golden section search (GSS) based MPPT control and its application with three-level DC-DC boost converter for MPPT are demonstrated. The three-level boost converter provides the high voltage transfer which enables the high power PV system to work with low size inductors with high efficiency. The balancing of the voltage across the two capacitors of the converter and MPPT is achieved using a simple duty cycle based voltage controller. Detailed simulation of three-level DC-DC converter topology with GSS algorithm is carried out in MATLAB/SIMULINK platform. The validation of the proposed system is done by the experiments carried out on hardware prototype of 100 W converter with low cost AT’mega328 controller as a core controller. From the results, the proposed system suits as one of the solutions for PV based generation system and the experimental results show high performance, such as a conversion efficiency of 94%.


2005 ◽  
Vol 498-499 ◽  
pp. 676-680 ◽  
Author(s):  
A.A. Fernandes ◽  
E.U.C. Frajndlich ◽  
Humberto Gracher Riella

The high pure synthetic zeolite have a large application in industry and agriculture, being nowadays in majority imported in Brazil. The biomass like rice hull ash (RHA), a rice industry waste, can be real advantageous in manufacture of different materials, since that is produced in large scale in the country. The silica extraction from RHA by alkaline leaching is a low energetic coast process and high efficiency, obtaining high pure silica with high reactive amorphous structure, very interesting for zeolite production. In this work was developed a economically feasible route for the production of high purity and crystallinity ZSM-5 zeolite, free of expensive template, starting from a low value intake, a industrial waste, producing a high value materials. The extracted silica from RHA in sodium silicate form is precipitated in the proper zeolite formation reactional mixture. The ZSM-5 have a lot of industrial applications due your high selectivity in catalytic reactions and high thermal and acid stability.


Author(s):  
Yi Zheng ◽  
Zhi-Zhu He ◽  
Jun Yang ◽  
Jing Liu

The advancement of printed electronics technology has significantly facilitated the development of electronic engineering. However, so far there still remain big barriers to impede the currently available printing technologies from being extensively used. Many of the difficulties came from the factors like: complicated ink-configurations, high post-treatment temperature, poor conductivity in room temperature and extremely high cost and time consuming fabrication process. From an alternative strategy, our recently invented desktop liquid metal printer offered a flexible way to better address the above deficiencies. Through modifying the system developed in the authors’ lab, here we demonstrated the feasibility of the method in quickly and reliably printing out various large area electronic circuits. Particularly, the liquid metal ink made of GaIn24.5 alloy, with a high electrical resistivity of 2.98×10−7 Ω·m, can be rapidly printed on polyvinyl chloride (PVC) substrate with maximum sizes spanning from centimeter size to meter large. Most important of all, all these manufactures were achieved at an extremely low cost level which clearly shows the ubiquitous value of the liquid metal printer. To evaluate the working performance of the present electronics fabrication method, the electrical resistance and wire width of the printed circuits were investigated under multiple overprinting cycles. For practical illustration purpose, LED lighting conductive patterns which can serve as a functional electronic decoration art were fabricated on the flexible plastic substrate. The present work sets up an example for directly making large-scale ending consumer electronics via a high-efficiency and low-cost way.


2015 ◽  
Vol 4 (4) ◽  
Author(s):  
Baohua Jia

AbstractLight management plays an important role in high-performance solar cells. Nanostructures that could effectively trap light offer great potential in improving the conversion efficiency of solar cells with much reduced material usage. Developing low-cost and large-scale nanostructures integratable with solar cells, thus, promises new solutions for high efficiency and low-cost solar energy harvesting. In this paper, we review the exciting progress in this field, in particular, in the market, dominating silicon solar cells and pointing out challenges and future trends.


2021 ◽  
Vol 9 ◽  
Author(s):  
Kai Li ◽  
Chao Teng ◽  
Shuang Wang ◽  
Qianhao Min

Photocatalytic conversion of CO2 into solar fuels has gained increasing attention due to its great potential for alleviating the energy and environmental crisis at the same time. The low-cost TiO2 with suitable band structure and high resistibility to light corrosion has proven to be very promising for photoreduction of CO2 using water as the source of electrons and protons. However, the narrow spectral response range (ultraviolet region only) as well as the rapid recombination of photo-induced electron-hole pairs within pristine TiO2 results in the low utilization of solar energy and limited photocatalytic efficiency. Besides, its low selectivity toward photoreduction products of CO2 should also be improved. Combination of TiO2 with other photoelectric active materials, such as metal oxide/sulfide semiconductors, metal nanoparticles and carbon-based nanostructures, for the construction of well-defined heterostructures can enhance the quantum efficiency significantly by promoting visible light adsorption, facilitating charge transfer and suppressing the recombination of charge carriers, resulting in the enhanced photocatalytic performance of the composite photocatalytic system. In addition, the adsorption and activation of CO2 on these heterojunctions are also promoted, therefore enhancing the turnover frequency (TOF) of CO2 molecules, so as to the improved selectivity of photoreduction products. This review focus on the recent advances of photocatalytic CO2 reduction via TiO2-based heterojunctions with water oxidation. The rational design, fabrication, photocatalytic performance and CO2 photoreduction mechanisms of typical TiO2-based heterojunctions, including semiconductor-semiconductor (S-S), semiconductor-metal (S-M), semiconductor-carbon group (S-C) and multicomponent heterojunction are reviewed and discussed. Moreover, the TiO2-based phase heterojunction and facet heterojunction are also summarized and analyzed. In the end, the current challenges and future prospects of the TiO2-based heterostructures for photoreduction of CO2 with high efficiency, even for practical application are discussed.


2021 ◽  
Author(s):  
Yang Liu ◽  
Joost Berkhong

An easily available heterogeneous semiconductor material, g-CN, proved to be feasible when combined with homogeneous nickel catalysts for light-mediated C(sp2)-SO2Ar bond formation of aryl bromides with aryl sulfinates under mild conditions and base-free, unlocking a variety of cross-couplings. The metal-free heterogeneous semiconductor is totally recyclable from reaction system, and experimental results demonstrated a series of differently substituted substrates including electron donating groups and electron withdrawing groups can be tolerated with a satisfactory result. The method could even pro-duce the classic drug Dapsone in large scale, showing strong practical application potential.


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