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991.
We have applied density functional theory to study the electronic structure changes caused by Nb incorporation in BiVO4 and the application of external pressure. The overall solubility of Nb in BiVO4 is usually high, and the presence of oxygen vacancies affect the dopability of Nb in BiVO4. Through the analyses of the chemical-potential landscape, we have determined the single-phase stability zone of BiVO4 with the Nb doping. The most favorable Nb doping is simultaneous substitutions at both V- and Bi-sites. Even though Nb substitution at only V-site is next favorable, the band gap change is not very significant which agrees with an earlier experiment. However, it does change the electron effective mass by 20 % owing to the presence of Nb 4d bands in the conduction bands, which explains better catalytic activity by Nb-doped BiVO4. In addition, application of external pressure the single-phase stability zone in the chemical-potential landscape. We have also focused on the local structural distortions near the Nb doping site, especially on the BiO8 octahedra. We have shown here that pressure-induced symmetrization of BiO8 dodecahedron lowers the electron's effective mass further and therefore can help to improve the photoconduction property of BiVO4. 相似文献
992.
Dr. Raheela Naz Prof. Qinglei Liu Dr. Waseem Abbas Dr. Muhammad Imtiaz Dr. Imran Zada Dr. Javed Ahmad Dr. Tengfei Li Prof. Jiajun Gu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(70):16054-16062
A new ternary composite of 1T-molybdenum disulfide, hexagonal tungsten trioxide, and reduced graphene oxide (M-W-rGO) is synthesized by using a one-pot hydrothermal process. The synergetic effect of 1T-MoS2 and hexa-WO3 nanoflowers improves the electrochemical performance for supercapacitors by inducing additional active sites and hexagonal tunnels, respectively, which lead to high storage capacity and easy transfer of electrolyte ions. The ternary M-W-rGO composite has a high specific capacitance of 836 F g−1 at 1 A g−1, which is nearly twice that of binary composites of M-rGO and W-rGO with high capacitance retention of 86.35 % after 3000 cycles at a high current density of 5 A g−1. This study provides a new ternary composite that can be used as an electrode material for high-performance supercapacitors. 相似文献
993.
Muhammad Ismail M.I. Khan Murad Ali Khan Kalsoom Akhtar Abdullah M. Asiri Sher Bahadar Khan 《应用有机金属化学》2019,33(8)
Ginger rhizome powder was used for the synthesis of supported metallic nanoparticle catalysts. A simple and novel adsorption method was used for the synthesis of silver nanoparticles loaded on ginger powder (Ag/GP), copper on ginger powder (Cu/GP) and nickel on ginger powder (Ni/GP). Among these, Ag/GP showed selective reduction of methyl orange and was used for further reactions. The prepared nanomaterials were characterized through X‐ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, fourier transform infrared spectroscopy and energy‐dispersive X‐ray spectroscopy. The prepared Ag/GP catalyst was employed in the catalytic reduction of 4‐nitrophenol (4‐NP), 2‐nitrophenol (2‐NP), rhodamine B, methyl red and congo red. Ag/GP showed excellent catalytic reduction activity, the rate constants being 1.26 × 10?3 and 2.38 × 10?3 s?1 for 2‐NP and 4‐NP, respectively. The turnover frequency reached 1.06 min?1 for 2‐NP and 1.16 min?1 for 4‐NP when using the Ag/GP catalyst. The prepared Ag/GP catalyst demonstrated outstanding activity for the degradation of a mixed solution of dyes. Also, stability and reusability of the prepared catalyst were investigated, which showed outstanding reusability up to five times and was stable up to five days. 相似文献
994.
Sami Ullah Humbul Suleman Muhammad Suleman Tahir Muhammad Sagir Shabbir Muhammad Abdullah G. Al-Sehemi Masood-ur-Rauf Zafar Firas A. Abdul Kareem Abdulhalim Shah Maulud Mohamad Azmi Bustam 《国际化学动力学杂志》2019,51(4):291-298
In this study, a new pressure drop method has been used to investigate the kinetics of carbon dioxide reaction with aqueous blend of 2-amino-2-ethyl-1,3-propanediol (AEPD) with piperazine (PZ). The blending of a small amount of PZ with AEPD has a significant effect on the observed rate constant, kobs. It was observed that kobs values of the blend increased more than twice than the summation of kobs values of individual alkanolamines. The reaction kinetics in this study were modeled by assuming a termolecular mechanism. The addition of 0.1 mol/L of PZ to 1 mol/L AEPD exhibited an observed rate constant, kobs of 8824.1 s−1, which is comparable to other alkanolamine mixtures. Hence, PZ/AEPD mixtures can be potentially used for rapid carbon dioxide capture. 相似文献
995.
Yong Wang Katerina Szokolova Dr. Muhammad Zafir Mohamad Nasir Prof. Zdenek Sofer Prof. Martin Pumera 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(30):7330-7338
Group 6 transition metal dichalcogenides (TMDs), such as MoS2 and WS2 have been extensively studied for various applications while few studies have delved into other TMDs such as platinum dichalcogenides. In this work, layered crystalline and amorphous platinum disulfide (PtS2) were synthesized, characterised and their fundamental electrochemical properties were investigated. Both materials exhibited inherent oxidation and reduction reactions which would limit their operating potential window for sensing applications. Amorphous phase materials are considered to be promising electrocatalysts due to the porous, and nanostructured morphology with high concentration of unsaturated active sites. The electrocatalytic performances towards oxygen reduction (ORR) and hydrogen evolution reactions (HER) of crystalline and amorphous PtS2 were analysed. Amorphous PtS2 was found to exhibit superior electrocatalytic performances towards ORR and HER as compared to crystalline PtS2. For HER, amorphous and crystalline PtS2 have overpotential values of 0.30 V and 0.70 V (vs. RHE) at current density of 10 mA cm−2, respectively. The influence of electrochemical reduction pre-treatment on their catalytic behaviours was also investigated. Electrochemical reduction pre-treatment on both crystalline and amorphous PtS2 removed the oxidized sulfate groups and increased the proportion of Pt0 oxidation state which exposed more catalytic sites. As such, these materials were activated and displayed improved ORR and HER performances. Electrochemically reduced amorphous PtS2 outperformed the untreated counterparts and exhibited the best HER performance with overpotential of 0.17 V (vs. RHE) at current density of −10 mA cm−2. These findings provide insights into the electrochemical properties of noble metal PtS2 in both crystalline and amorphous states which can be activated by electrochemical reduction pre-treatment. 相似文献
996.
Aliero Muhammad Saidu Qureshi Kashif Naseer Pasha Muhammad Fermi Ghani Imran Yauri Rufai Aliyu 《Wireless Personal Communications》2021,119(3):2017-2053
Wireless Personal Communications - Currently building structure sector takes lead in energy consumption across the globe and is expected to increase by 2% every year. Consequently, being a major... 相似文献
997.
Hüseyin Budak Samet Erden Muhammad Aamir Ali 《Mathematical Methods in the Applied Sciences》2021,44(1):378-390
We first establish two new identities, based on the kernel functions with either two section or three sections, involving quantum integrals by using new definition of quantum derivative. Then, some new inequalities related to Simpson's 1/3 formula for convex mappings are provided. In addition, Newton type inequalities, for functions whose quantum derivatives in modulus or their powers are convex, are deduced. We also mention that the results in this work generalize inequalities given in earlier study. 相似文献
998.
Raza Ali Nawaz Syed Junaid Ahmed Abrar Wyne Shurjeel Muhammad Bilal Patwary Mohmammad N. Prasad Ramjee 《Wireless Personal Communications》2022,122(4):3545-3571
Wireless Personal Communications - Non-orthogonal multiple access (NOMA) scheme, potentially enabling high spectral efficiency, is one of the key technological innovations in the 5th generation... 相似文献
999.
Ahmed Naveed Bakar Kamalrulnizam Abu Zuhra Fatima Tul Kehkashan Tanzila Mujahid Muhammad Akram Rathore Muhammad Siraj Dawood Muhammad Isyaku Babangida 《International Journal of Wireless Information Networks》2022,29(3):314-340
International Journal of Wireless Information Networks - Due to fast development in digital systems, the traditional network architecture is becoming inadequate for the requirements of new... 相似文献
1000.
Thermopower Study of GaN-Based Materials for Next-Generation Thermoelectric Devices and Applications
Elisa N. Hurwitz Muhammad Asghar Andrew Melton Bahadir Kucukgok Liqin Su Mateusz Orocz Muhammad Jamil Na Lu Ian T. Ferguson 《Journal of Electronic Materials》2011,40(5):513-517
III-nitride InGaN-based solar cells have gained importance because their band gap can potentially cover most of the solar
spectrum, spanning 0.7 eV to 3.4 eV. However, to use these materials to harvest additional energy, other properties such as
their thermoelectric properties should be exploited. In this work, the Seebeck coefficient and the electrical conductivity
of three InGaN alloys with various indium concentrations and Gd-doped GaN (GaN:Gd) were measured, and the power factor was
calculated. We report a Seebeck value of ∼209 μV/K for Gd-doped GaN. 相似文献