bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Electrocatalysts for Generating Oxygen from Acid Water Electrolysis
Authors: Chatterjee Kuntal , Wu Jingjie , Shen Jianfeng , Hackenberg Ken , Vajtai Robert , Lou Jun , Ajayan Pulickel M 
Published: February 2020

Rapidly increasing global energy demand and developing carbon-neutral economy impose great challenge to the scientific community and it requires untiring efforts to exploit and store abundant but diffuse renewable energy sources. One innovative and promising approach for that is the efficient production of hydrogen serving as fuel, through electricity-driven water splitting. However, the overall efficiency of the reaction is largely impeded by the kinetically sluggish oxygen evolution reaction (OER), imposing serious overpotential requirement. Therefore, an efficient oxygen evolution catalyst is essential to enhance the reaction rate and/ or lower the overpotential. Although precious metal oxides, such as RuO2 and IrO2, are considered to be the most active OER electrocatalysts, they are not suitable for large-scale applications because of their scarcity and high costs. So There is an ongoing interest to find earth-abundant and inexpensive electrocatalysts for OER. In response, non-noble transition-metal-based oxides, layered double hydroxides (LDH), perovskite-type metal oxides are some of the advance electrocatalyst candidates with their own limitations.
Here, for the first time, we focus on layered transition metal dicalchogenides (TMDs) like MoS2 and TaS2 in this search due to their natural abundance and high activity towards hydrogen evolution. We report MoS2 and TaS2, in both their 2H and 1T polymorphs that display excellent catalytic activity for OER in much required acid medium. They are chemically exfoliated to thinner nanosheets from MoS2 precursor and TaS2 nanostructures synthesized by chemical vapour deposition. Structural and electrochemical studies reveal their corresponding semiconducting 2H and metallic 1T polymorph and the impressive electrocatalytic performance respectively. The proliferation of active sites is such a high for those materials that an electrocatalytic current density of 10 mA cm−
2 is achievable with overpotential much lower than that of the benchmark IrO2 or RuO2OER catalyst. The Tafel slopes found for the different samples are also in good rivalry of the benchmark catalyst. The performances are also analyzed on the basis of their probable structure relation.
This work presents general strategies to grow nanostructures of layered TMD materials for the enhanced catalytic performance in OER and open up a new avenue in the pursuance of water splitting research towards the growth of hydrogen economy.
Tuning the Composition and Structure of Metallic Nanotubes for Electrocatalysis
Authors: Papandrew Alexander B. , Atkinson Robert W. , St. John Samuel , Unocic Raymond R , Zawodzinski Thomas A. 
Published: February 2020

Recent trends in the design of electrocatalysts for power generation systems have highlighted the usefulness of supportless extended surfaces, surface-segregated alloys, and shape-controlled particles for activity enhancement1. Multiple synthetic schemes have been devised to produce these materials with varying degrees of versatility and scalability.
We have investigated templated vapor deposition as an addition to the already wide array of synthetic strategies, and applied these methods to problems in low-temperature electrocatalysis. In our approach, metalorganic precursors are used to deposit conformal nanoparticulate films within the internal channels of porous anodic alumina templates. By sequentially depositing multiple species, layered structures can be formed. Subsequent thermal treatments can then be used to drive crystallite growth, alloying (or phase separation) and mesostructural evolution. The template structure is then dissolved to release high-aspect ratio nanotubes that can be implemented as electrocatalysts (Figure 1).
By rationally selecting the constituent metals, relative compositions, and heat treatment temperatures, we synthesized highly active electrocatalysts for multiple reactions of technological interest. These include the use of pure Pt nanotubes2 for acidic oxygen reduction, Bi-decorated Pd nanotubes for formic oxidation, Pt-Ru nanotubes for methanol oxidation3and, recently, Ru-Pt nanotubes for hydrogen oxidation in alkaline electrolytes.
In this contribution we examine the unique characteristics of the novel class of electrocatalysts emerging from our templated vapor deposition methods. Comprehensive characterization of the catalysts using chemical and structural probes including advanced transmission electron microscopy are used to gain insight into the structure-property relationships governing nanotube activity. Finally, future prospects for the synthesis of additional functional nanostructures for electrochemical systems will be discussed.
References

1 M. K. Debe, Nature 486, 43–51 (2012).

2 A. B. Papandrew, R. W. Atkinson, G. a. Goenaga, S. S. Kocha, J. W. Zack, B. S. Pivovar, and T. A. Zawodzinski, J. Electrochem. Soc. 160, F848–F852 (2013).

3 R. W. Atkinson, R. R. Unocic, K. A. Unocic, G. M. Veith, T. A. Zawodzinski, and A. B Papandrew, ACS Appl. Mater. Interfaces DOI: 10.1021/am508228b (2015).

Figure 1
Aligning Silicon Nanopillar Formed in Electroless HF/H2O2 Etching through Pre-Forming Porous Layer
Authors: Chiang C. -C. , Xu Dawei , Huang Y.-C , Juan P.- C. , Lo F. -S. , Hu Hui-Qin , He Cheng-Long , Lee T. -H. 
Published: February 2020

For fabricating a controllable nanopillar array structure by utilizing the metal-assisted etching technique, we created a fine porous cladding layer on the surface of bulk silicon to settle down silver nanoparticles.
Prior to metal-assisted etching process, a 10nm thick porous silicon layer was produced on the surface of a p-type, 1-10 Ohm-cm, (100) bulk silicon by HF based electrochemically etching and then rinsed by D.I. water. After spin-drying, the specimen and a same silicon specimen but without the porous layer were dipped in a solution (HF / AgNO3 / H2O) for 30 seconds for the nucleation of silver nanoparticles. The dipped specimens were then etched by HF/ H2O2/ H2O solution for forming nanopillar.
Through the observation of Field Emission Scanning Electronic Microscopy (FE-SEM), we found the pores on the surface of the porous layer could provide priority nucleation sites for silver nanoparticles. Hence, we could achieve a designed silicon nanopillar array by controlling the formation of the porous layer. After etching, the silicon specimen with the pre-forming porous layer exhibits different characteristic from the one without the layer as shown in figure.

Figure 1
Platinum-Based Alloy and Ionic Liquid Composites Dispersed on Carbon Black As a Synergistic Catalyst for Oxygen Reduction Reaction
Authors: Tran Quoc-Chinh , Choi Ho-Suk 
Published: February 2020

Catalysts for oxygen reduction are of great interest in the field of renewable energy technology such as fuel cell, which can provide the power for future electric vehicles. Herein, we report a one-pot synthesis of composite material consisting of platinum(Pt)-based alloy and ionic liquid dispersed on carbon black (SuperP) in 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide through using one atmospheric pressure plasma. The PtNi-NPs with the size of 2–3 nm were stably and uniformly hybridized on the surface of carbon blacks, which were also covered with ionic liquid layer. The incorporation of PtNi alloy with a hydrophobic and protic ionic liquid layer shows good electrocatalytic activity due to the high O2 solubility of the ionic liquid, resulting in high frequency and high mass activity of oxygen reduction reaction (ORR), which is better than that of commercial Pt/C catalysts. The PtNiRu-ionic liquid/carbon black catalyst (Figure 1) also shows better stability than the commercial Pt/C under the same ORR condition as seen in Figure 2. The results prove that the Pt-based alloy and ionic liquid composites dispersed on carbon black push the ORR towards completion and can indeed be one of promising candidates for many electrochemical catalytic applications.

Figure 1
Plasmon-Mediated Surface Chemistry for Solar Photocatalysis
Authors: Wei Wei David 
Published: February 2020

Using sunlight to facilitate and promote valuable chemical reactions is an ideal solution to the challenge of meeting future energy demands. Our group aims to address fundamental questions concerning surface plasmon resonance (SPR)-mediated interfacial electron transfer (ET) and photothermal heating in order to develop new materials and strategies for efficiently converting solar energy to chemical energy. In this talk, I will show how we unambiguously reveal the mechanics of plasmon-mediated electron transfer (PMET) in Au/TiO2 heterostructures under visible light (λ > 515 nm) during in situ operation. I will further discuss how we directly probe the relaxation dynamics and energetics of the transferred “effective hot electrons” that participate in photocatalytic reactions. I will explore some strategies for manipulating “hot electrons” for the rational design and construction of a new class of multi-component solar photocatalysts for efficiently producing H2 from water.
Solar to Fuels Conversion By a Monolithic and Standalone Photoelectrochemical Device
Authors: Jeon Hyo Sang , Hwang Yun Jeong , Min Byoung Koun 
Published: February 2020

Solar to fuels conversion inspired from nature has attracted substantial attention due to a demand for developing sustainable future energy as well as chemical resources. In this presentation, I will introduce our strategy for a highly efficient solar energy to chemical conversion device using CO2 and water as feedstock. For the realization of this architecture we developed a thin film photovoltaic technology for the light absorbing component using a low cost, solution based Cu(InxGa1-x)(SySe1-y)2 (CIGS) fabrication method to provide high enough potential for the conversion reactions. Our solar-fuel device also adapted metal oxide nanoparticle deposited with a low temperature coating method as the water oxidation catalyst and nanostructured metal films as the CO2 reduction to CO or HCOOH generation catalyst. Remarkably, this is the first demonstration of a monolithic and standalone solar-fuel device whose solar-to-fuel conversion efficiency from CO2 and H2O is over 4%, which is comparable to that of photosynthesis in nature. The details of the synthetic method and characterization of each component and the solar-fuel generation system are discussed. Also, some prospects of solar-fuel research for achieving highly efficient solar-fuel production device will be suggested.
Electronic Band Structure and Charge Transfer in Semiconductors
Authors: Wu Nianqiang , Cushing Scott Kevin 
Published: February 2020

Semiconductor has been widely used in photocatalytic and photovoltaic devices. The electronic band structure governs the charge separation, charge migration and charge recombination processes. This talk provides an insight into the band gap, the deep and shallow level states in the band gap and the surface trap states that play important roles in the processes of photo-generated charge carriers in the metal oxide semiconductors. Also, this talk demonstrates how to engineer the bulk band structure and the surface states in order to enhance the solar energy conversion.
Developing Catalysts for the Selective Electrochemical Reduction of Carbon Dioxide to C2 and C3 Products
Authors: Yeo Boon Siang 
Published: February 2020

The electrochemical reduction of carbon dioxide (CO2) to hydrocarbons and alcohols using copper catalysts is a promising way to produce valuable carbon fuels and chemical feedstocks. However, the selectivity for this process is still rather poor. Here, we present our recent efforts to develop Cu-based catalysts for the electroreduction of CO2 to target molecules such as ethylene, ethanol, and propanol. In the case of CO2 reduction to ethylene and ethanol, we found that their faradaic yields can be systematically tuned by changing the thickness of the deposited Cu2O overlayers. 1.7-3.6 μm thick films exhibited the best selectivity for these C2 compounds at -0.99 V vs. RHE, with faradaic efficiencies of 34-39% for ethylene and 9-16% for ethanol. Less than 1% methane was formed. A high C2H4/CH4 products’ ratio of up to ~100 could be achieved. Scanning electron microscopy, X-ray diffraction and in-situ Raman spectroscopy revealed that the Cu2O films reduced rapidly and remained as metallic Cu0 particles during the CO2 reduction. The selectivity trends exhibited by the catalysts during CO2 reduction in phosphate buffer and KHCO3 electrolytes suggest that an increase in local pH at the surface of the electrode is not the only factor in enhancing the formation of C2 products. An optimized surface population of edges and steps on the catalyst is also necessary to facilitate the dissociation of CO2 and the dimerization of the pertinent CHxO intermediates to ethylene and ethanol. We also demonstrate in this presentation the importance of defects in the formation of propanol from CO2 reduction.
Reference: Ren D, Deng Y, Handoko AD, Chen CS, Malkhandi S and Yeo BS. Selective Electrochemical Reduction of Carbon Dioxide to Ethylene and Ethanol on Copper (I) Oxide Catalysts. ACS Catal. 2015, 5, 2814-2821
Preparation of Nickel Tungstate (NiWO4) Nanoparticles and Characterization with Electrochemical Methods in Combination with Mott-Schottky Theory
Authors: Hosseini Seyyedamirhossein , Farsi Hossein , Moghiminia Shokoufeh , Li Zhihai 
Published: February 2020

Nickel tungstate is an interesting semiconductor for application in solar cell owing to its low band gap1, high mechanical stability and abundant oxygen sites (4 oxygen/Ni-W) for dye molecule absorption. Nanoparticle nickel tungstate has been synthesized with different methods including solid state2, direct mechanical rout3 and standard ceramic rout4. In current study nickel tungstate has been synthesized with different particle size distribution using co-precipitation5 method (N1) and in microemulsion medium in presence of cetyltrimethylammonium bromide (CTAB) as surfactant (N2).
Synthesized samples were examined using XRD, TEM and DRS methods. Electrochemical impedance spectroscopy method in combination with mott-schottky theory has been applied for determination of electronic specification of all samples. Furthermore, light transformation efficiency of samples for application in solar cell has been studied using gratzel two-electrode cell.

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Cost Effective Inkjet Printing of Titania Nanoparticles for Photocatalytic Applications
Authors: Bernasconi Roberto , Magagnin Luca 
Published: February 2020

Titania is one of the most promising materials in the field of light induced catalysis on surfaces. In the last decades researchers investigated in particular applications like self-cleaning and photochemical degradation of pollutants. Moreover titania present antibacterial properties, which allows to consider uses in the biomedical field. The most immediate method to produce titania coatings is the anodization of a titanium substrate, which is able to provide good results in terms of quality and reproducibility. Alternative methods to employ titania when a titanium substrate cannot be provided have been developed as well, including TiO2 codeposition with metals, sol-gel deposition and inkjet printing. In particular inkjet printing of titania nanoparticles is of great interest due to the possibility of creating patterns in an easy and cheap way, controlling the thickness of the deposited layer with good accuracy. TiO2 inkjet printing has been attempted in the past mainly using laboratory printers, with good results in terms of photocatalytic and antimicrobial activity. Possible challenges for the future are the optimization of the method and the use of widely available office inkjet printers to increase the flexibility of the process.
The present work aims at depositing titania from a commercial office inkjet printer, modified to use custom made inks containing nanoparticles obtained by sol-gel synthesis. The nanoparticles of titania thus obtained are characterized via TEM to quantify the mean size and the diameters distribution. The subsequent formulation of the printing inks is done following the specifications of the corresponding pigmented inks used in standard printing on paper. In particular viscosity and surface tension are measured and modified to obtain the best printing quality. Finally the printed layers, either in form of continuous samples or patterns, are characterized from the morphological point of view and their photocatalytic efficiency is tested. Moreover, as preliminary results, the printed layers are tested on conductive substrates for electrophotocatalysis as well.
Nanomaterials-Based Biosensors for Biomedical and Food Safety Applications
Authors: Song Yang , Li He , Zhu Chengzhou , Du Dan , Lin Yuehe 
Published: February 2020

Nanoparticles, graphene and graphene-like 2D nanomaterials have attracted tremendous research interest in the field of bioanalytical chemistry due to their intrinsic properties, including the electronic, optical, and mechanical properties associated with their nanostructures. The marriage of nanotechnology and biosensors has created many ingenious biosensing strategies for applications in the areas of biomedical diagnosis and food safety. In this talk, I will give an overview of the recent advances in the development of graphene and graphene-like 2 D nanomaterial-base biosensors and peroxidase-like bimetallic nanoparticles for biosensing. Special attention will be paid to nanomaterials-based enzyme biosensors, immunosensors, and DNA biosensors. Future perspectives on high-performance nanomaterials-based biosensors in biomedical and food safety applications will be are discussed.
A Comparison of the Sensor Performance of Electrochemical Peptide-Based Sensors Fabricated from 6- or 11-Carbon Self-Assembled Monolayers
Authors: Sutlief Arin L , Lai Rebecca Y. 
Published: February 2020

In this study, we compare the sensor performance of two electrochemical peptide-based (E-PB) sensors fabricated using peptide probes modified with a 6- or 11-carbon alkanethiol linker. The biorecognition probe is a highly antigenic peptide sequence in the HIV-1 p24 antigen, and the target is the antibody generated against this antigen (anti-p24 antibody). When compared to the C11-based sensor, the C6-based sensor shows higher signal suppression in the presence of the correct target. In addition, the C6-based sensor is also regenerable and can be reused for over 3 times. Despite the reduced signaling capability and the lack of regenerability, the C11-based sensor is slightly more specific for the target antibody. While there are advantages and disadvantages associated with each of the two systems, with proper optimization, both sensors can potentially be used for real time detection of HIV infections.

Figure 1
Wireless Sensors and Actuators Based on Magnetostrictive Resonators
Authors: Zhang Kewei , Zhang Lin , Cheng Z.-Y. 
Published: February 2020

Biosensors based on magnetostrictive resonators, magnetostrictive cantilever and magnetostrictive particles (MSPs), have been developed in recent years [1]. Due to their magnetic nature, these biosensors are wireless, which makes them to a great candidate for in-situ detection. Both phage and antibody, which are immobilized onto the surface of the magnetostrictive resonator, have been used as biological molecular recognition elements. The performance characterization of these biosensors shows that these biosensors work well in liquid and exhibit a high sensitivity for the detection of bacteria in water [2].
It is well known that the sensitivity of MSP increases with reducing size of the MSP. Therefore, a much better sensitivity is expected for the MSPs with a smaller size. The above results demonstrate that the biosensors based on the magnetostrictive resonators are suitable for in-situ detection of pathogens in liquid media. To fully develop the detection technology based on magnetostrictive resonators for in-field detection, a small size interrogation unit/device is required. A new methodology was developed recently [3]. Based on this technology, a handheld device is developed to characterize the response of the biosensors based on magnetostrictive resonators.
For the detection of pathogenic species in food samples, sampling is always a key issue, since the locations of the target species are unknown and the biosensors have to be brought into reaction with the target species. It is experimentally found that an MSP biosensor can act as an actuator when it is driven under a frequency different than the resonant frequency. In the experiments, it is found that the moving speed of the MSP actuator is dependent on the frequency. A freestanding MSP is an actuator that can move along its length direction without the limitation in displacement and the motion can be both directions.
REFERENCES
[1] K. W. Zhang, L. Zhang, L. L. Fu, S. Q. Li, H. Q. Chen, and Z.-Y. Cheng, Magnetostrictive resonators as sensors and actuators, Sensors & Actuators: A. Physical,
200, 2-10 (2013).
[2] K. W. Zhang, L. L. Fu, L. Zhang, Z.-Y. Cheng, and T.-S. Huang, Magnetostrictive particle based biosensors for in-situ and real-time detection of pathogens in water, Biotechnology and Bioengineering, 111, 2229 (2014).
[3] Z.Y. Cheng, A.X. Zhang, K.W. Zhang, B.A. Chin, Systems for Characterizing Resonance Behavior of Magnetostrictive Resonator(s), U.S. Patent Application
No. 20120280682 (2012).