Southwest University of Science and Technology

About: Southwest University of Science and Technology is a education organization based out in Mianyang, China. It is known for research contribution in the topics: Adsorption & Graphene. The organization has 10017 authors who have published 8923 publications receiving 94850 citations. The organization is also known as: Xīnán Kējìdàxué.

Synergistically enhanced photocatalytic performance of Bi 4 Ti 3 O 12 nanosheets by Au and Ag nanoparticles

Abstract: In this work, we attempted to assemble Au and Ag nanoparticles (NPs) with different sizes onto Bi4Ti3O12 (BTO) nanosheets with the aim of synergistically enhancing the photocatalytic performance. The as-prepared Au–Ag@BTO composite was systematically characterized by means of TEM, XRD, XPS, FTIR, UV–vis DRS, PL spectroscopy, EIS and photocurrent spectroscopy. The TEM observation demonstrates that larger-sized Au NPs (average size: 20 nm) and smaller-sized Ag NPs (average size: 8 nm) are uniformly decorated on the surface of BTO nanosheets. Compared to bare BTO, the Au–Ag@BTO composite manifests an increased visible light absorption, increased bandgap, increased photocurrent density, decreased charge-transfer resistance and decreased PL intensity. Separately using simulated sunlight, UV light and visible light as the light source, the photocatalytic performance of the composite was evaluated by the degradation of RhB. An enhanced photocatalytic performance of the composite is observed in all the cases. Under UV irradiation, the photocatalytic enhancement is mainly ascribed to the efficient separation of photogenerated electron/hole pairs caused by the smaller-sized Ag NPs, whereas the photocatalytic enhancement under visible light irradiation is dominantly due to the LSPR effects of the larger-sized Au NPs. The synergistic photocatalytic enhancement between Ag and Au NPs is achieved under simulated sunlight irradiation. Active species trapping experiments were carried out, revealing that photogenerated holes and ·O2− radicals play a dominant and secondary role in the photocatalysis, respectively.

Dual band visible metamaterial absorbers based on four identical ring patches

Abstract: This paper proposes a dual-frequency tunable ideal visible light metamaterial absorber based on the sub-wavelength range, which achieves perfect absorption in the visible light band. The absorber consists of an Au reflector and a nodal (SiO2) layer, and a top Au absorber layer. The absorption structure on the top of the absorber adopts the style of ancient Chinese coins and forms a square arrays structure. As a result, the absorber's two absorption peaks are perfect absorption peaks, and the absorption rate can reach 99.9%. In addition, we also researched the influence of adjusting the absorber's geometric parameters on the absorber, and analyzed the absorption mechanism under different circumstances. Through research, it can be known that the absorber has near-perfect dual-band absorption characteristics that do not depend on polarization angle and incident angle insensitivity. Therefore, the absorber designed by us will have a broad application prospect in the filter, solar cell, and so on.

Red-blood-cell-like (NH4)[Fe2(OH)(PO4)2]·2H2O particles: fabrication and application in high-performance LiFePO4 cathode materials

Abstract: A well-crystallized (NH4)[Fe2(OH)(PO4)2]·2H2O particle with a red-blood-cell-like (RBC-like) shape has been synthesized via a simple sonochemical method, and is employed as the precursor to fabricate LiFePO4/C as a cathode material for Li-ion batteries. The morphology evolution of (NH4)[Fe2(OH)(PO4)2]·2H2O from a nanoparticle to a nanoplate (∼50 nm in thickness) and to a RBC-like discoid is observed by increasing the reaction time. The formation mechanism of this kind of RBC-like shape can be understood as nucleation, crystallization, formation of thin plates, and self-assembly. The precursor and corresponding LiFePO4/C are characterized by XRD, SEM, TEM, charge–discharge tests and CV measurements. The results show that the morphology of the (NH4)[Fe2(OH)(PO4)2]·2H2O precursor turns from a RBC-like structure into an irregular structure and the size becomes much smaller for LiFePO4/C during the solid-state reaction process. The fabricated LiFePO4/C exhibits excellent rate performance with a discharge capacity of 113.4 mA h g−1 even at 10C and a capacity fading rate of 3.5% after 300 cycles. Thus, this kind of uniquely shaped (NH4)[Fe2(OH)(PO4)2]·2H2O shows potential application in high-power Li-ion batteries.

Dual-Band Infrared Perfect Absorber Based on a Ag-Dielectric-Ag Multilayer Films with Nanoring Grooves Arrays

Abstract: In this paper, we demonstrate a dual-band metamaterial perfect absorber based on a Ag-dielectric-Ag multilayer nanostructure. The structure of top metal film covers nanoring grooves array. A dielectric layer has a function of confining electromagnetic fields. Theoretical analysis shows that two absorption peaks (1059 nm and 1304 nm) with the absorption of 99.2% and 99.9% have been achieved, respectively. The physical origin of perfect absorption peaks are related to the Fabry-Perot resonance effect and localized surface plasmon resonance (LSPR) of the nanoring grooves. Its perfect absorption and resonance wavelength can be well regulated by adjusting the relevant structural parameters. Additionally, the absorber demonstrates good operation angle-polarization-tolerance at wide incident angles (0–60°). We believe that our design has a promising application in plasmon-enhanced photovoltaic, optical absorption switching, and modulator optical communications in the infrared regime.

Relationship between Corporate Social Responsibility and Financial Performance in the Mineral Industry: Evidence from Chinese Mineral Firms

Abstract: This paper examines the relationship between Corporate Social Responsibility (CSR) and Corporate Financial Performance (CFP) using panel data for 228 Chinese mineral listed firms from 2010 to 2013 with Pooled Least Squares regression analysis. Our study considers five different sublevel CSR issues—shareholder responsibility, employee responsibility, environmental responsibility, public responsibility, and supplier, customer and consumer responsibility—in capturing the effects of CSR elements on CFP. The estimation results show the different effects of each sublevel CSR issue on CFP. Overall, shareholder, employee responsibility, environmental responsibility, supplier, customer and consumer responsibility have significant relationships with CFP, which are the stakeholders who have the closest linkage with firm operations. Meanwhile, public responsibility outside the firm does not show significant interaction with CFP, which is why many mineral firms ignore the public interest and this leads to conflicts. Shareholder responsibility has the most significant positive effect on CFP. Supplier, customer and consumer responsibility and environmental responsibility usually have negative effects on CFP as costs increase. Moreover, all 228 listed mineral firms that were selected in this paper have been classified into five sub-sectors: the extractive industry, metal fabrication industry, oil and gas industry, gas and water-related industry, and oil-producing equipment industry, based on the Industry Classification Benchmark (ICB). Our study shows that the differences in the relationship between CSR and CFP for five sublevel industries are due to industry characteristics. If the government wants to solve these conflicts and positively encourage firms to adopt CSR, it is necessary to create a mining development environment whereby firm profits are closely tied to CSR.