Influence of electron releasing groups in benzylidene thiocarbohydrazide and their synergistic effect with iodide ions on acidizing corrosion inhibition of carbon steel in 15% HCl solution - Experimental and theoretical approach

385-401Influence of electron releasing groups in benzylidene thiocarbohydrazide and their synergetic effect with iodide ions on acidizing corrosion inhibition of carbon steel in 15% HCl using chemical and electrochemical methods has been studied. Tafel polarization measurements indicate that these compounds act as mixed-type inhibitors. The adsorption of these compounds obey Langmuir adsorption isotherm and the thermodynamic parameters are also calculated to explain their inhibitive action. The increase in synergism parameter (Sθ) indicates that the inhibition efficiency is improved in the presence of the iodide ions. Further, the density functional theory is used to validate the experimental results

Vertically Aligned Silicon Carbide Nanowires/Boron Nitride Cellulose Aerogel Networks Enhanced Thermal Conductivity and Electromagnetic Absorbing of Epoxy Composites

With the innovation of microelectronics technology, the heat dissipation problem inside the device will face a severe test. In this work, cellulose aerogel (CA) with highly enhanced thermal conductivity (TC) in vertical planes were successfully obtained by constructing a vertically aligned silicon carbide nanowires (SiC NWs)/boron nitride (BN) network via the ice template assisted strategy. The unique network structure of SiC NWs connected to BN ensures that the TC of the composite in the vertical direction reaches 2.21 W/(m·K) at a low hybrid filler loading of 16.69 wt, which was increased by 890 compared to pure epoxy (EP). In addition, relying on unique porous network structure of CA, EP based composite also showed higher TC than other comparative samples in the horizontal direction. Meanwhile, the composite exhibits good electrically insulating with a volume electrical resistivity about 2.35×1011 Ω·cm, and displays excellent electromagnetic wave absorption performance with a minimum reflection loss of -21.5 dB and a wide effective absorption bandwidth (< -10 dB) from 8.8 to 11.6 GHz. Therefore, this work provides a new strategy for manufacturing polymer-based composites with excellent multifunctional performances in microelectronic packaging applications

Development of a conjugated polyaniline incorporated electrospun poly(vinylidene fluoride-co-hexafluoropropylene) composite membrane electrolyte for high performance dye-sensitized solar cells

Different weight percentage (2, 3, 4, and 5 wt %) of polyaniline (PANI) were incorporated into electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) composite membranes (esCPMs). The regular morphology, molecular structure, crystallinity, porosity, electrolyte uptake, and leakage of the composite membranes were examined. The esCPMs were activated in liquid electrolyte containing 0.5 M LiI, 0.05 M I-2, and 0.5 M 4-tert-butylpyridine and 0.5 M 1-butyl-3-methylimidazoliun iodide in acetonitrile to afford electrospun PVdF-HFP/PANI composite membrane electrolytes (esCPMEs). The influence of different wt % of PANI on the esCPMEs was studied by electrochemical impedance measurements and Tafel polarization studies. The photovoltaic performance of a dye-sensitized solar cell assembled using 3 wt % PANI incorporated esCPME exhibits a higher power conversion efficiency of 7.20% than that assembled using esPME (=6.42%)

Mixed perovskites (2D/3D)-based solar cells: a review on crystallization and surface modification for enhanced efficiency and stability

Solar cells based on a three-dimensional (3D) crystalline perovskite framework exhibit desired photoconversion efficiency. However, 3D perovskites are prone to surface defects, leading to severe Shockley-Read-Hall (SRH) recombination and insufficient interactions between components, resulting in lower efficiency and stability. In contrast, two-dimensional (2D) perovskites have comparatively better excellent stability in hot and humid environments but suffer from lower efficiency. Recently, researchers reported that surface passivation of 3D perovskite by 2D perovskite improves the stability of solar cells without compromising their efficiency. In this review, the recent advances in surface modification of three-dimensional perovskites using two-dimensional perovskites are discussed. The crystal structures, photoelectric properties, and surface passivation strategies of 2D/3D perovskite solar cells with different components are systematically presented. Finally, the prospect of using two-dimensional perovskite passivation technology to further improve photovoltaic performance is discussed

Improving thermal conductivity of polyethylene/polypropylene by styrene-ethylene-propylene-styrene wrapping hexagonal boron nitride at the phase interface

In this work, the percentage of polyethylene (PE) and polypropylene (PP) blend is controlled at 50:50 to make the composite by forming a co-continuous structure with hexagonal boron nitride (h-BN). The h-BN is wrapped by thermoplastic elastomer styrene-ethylene-propylene-styrene (SEPS). This approach enables the localized distribution of h-BN at the interface of the co-continuous structure of PE/PP blend and SEPS phases, allowing the construction of a heat conduction path in the SEPS phase, thereby improving the thermal conductivity of PE/PP. Theoretical calculation predicted the localized distribution of SEPS at the interface of the PE/PP blend to form a co-continuous composite structure. The thermal conductivity of the composites can be improved by 57.7% by adding 10 wt% h-BN, presenting a commercial potential of such composites in certain heat dissipation applications

Highly efficient tetrametallic PtNiCuCo alloy nanoparticles for sensitive detection of hydrogen peroxide

The tetrametallic PtNiCuCo alloy nanoparticles were prepared by a simple and cost-effective solution-based approach and spray deposited on fluorine-doped tin oxide (FTO) substrates to use as a highly sensitive catalyst for hydrogen peroxide (H2O2) sensing. The morphological studies revealed that the PtNiCuCo nanoparticles had an average particle size of 5 +/- 1 nm. Electrochemical studies showed that PtNiCuCo nanoparticles possess excellent electro-oxidation activity for hydrogen peroxide at 20 mVs(-1) scanning rate (vs Ag/AgCl). The wide linear range for hydrogen peroxide (H2O2) was obtained from 10 mu M to 16 mM. The detection limits for H2O2 were 0.16 mu M (SNR = 3). The sensitivity of H2O2 was 4367.25 mu AmM-1 cm(-2). These results revealed that the prepared nanoparticles could be a potential candidate for H2O2 sensing

Influence of mass ratio and calcination temperature on physical and photoelectrochemical properties of ZnFe-layered double oxide/cobalt oxide heterojunction semiconductor for dye degradation applications

A visible light-active photoelectrocatalyst, ZnFe-layered double oxide (LDO)/cobalt(II,III) oxide (Co3O4) composites were obtained by calcining the Co loaded ZnFe-layered double hydroxide (LDH) prepared by a hydrothermal and microwave hydrothermal method. The morphological studies revealed that the ZnFe-LDO/Co3O4 composites exhibited a flower-like structure comprising Co3O4 nanowires and ZnFe-LDO nanosheets. Further, when the mass ratio of Co(NO3)2·6H2O/LDH was 1:1.8 and the calcination temperature was 550 oC, the ZnFe-LDO/Co3O4 composite exhibited 93.3% degradation efficiency for methylene blue (MB) at the applied voltage of 1.0 V under visible light after 3 h. Furthermore, the Mott-Schottky model experiments showed that the formation of a p-n heterojunction between ZnFe-LDO and Co3O4 could effectively inhibit the recombination of electrons and holes in the photoelectrocatalytic process. Meanwhile, free radical scavenging experiments showed that the active radicals of •OH played an important role in the degradation of MB. Therefore, the photoelectrocatalytic effect of ZnFe-LDO/Co3O4 provides a simple and effective strategy for the removal of organic pollutants

Hydrothermal Microwave Synthesis of Co3O4/In2O3 Nanostructures for Photoelectrocatalytic Reduction of Cr(VI)

Co3O4/In2O3 nanocomposites were prepared via a microwave-hydrothermal method and directly used as photoanodes for the photoelectrocatalytic (PEC) process to reduce Cr(VI). The as-prepared Co3O4/In2O3 composites show a rod-like structure, which is composed of nanoparticles. The PEC experiments indicated that after 120 min of irradiation with 0.7 V bias voltage and visible light, the Cr(VI) reduction efficiency of Co3O4/In2O3 composites in aqueous solution was 100%, which was superior to the samples prepared by other methods. Moreover, the Co3O4/In2O3 composite still had a high catalytic activity after five runs of PEC experiments. Elimination experiments demonstrate that photo-generated electrons (e–) performed a key role in the catalytic reduction of Cr(VI). The significantly improved PEC performance can be attributed to the bias voltage and the p-n heterojunction formed between Co3O4 and In2O3. Therefore, Co3O4/In2O3 nanocomposites have a considerable potential for the PEC reduction of Cr(VI)

Waterborne acrylic resin co-modified by itaconic acid and γ-methacryloxypropyl triisopropoxidesilane for improved mechanical properties, thermal stability, and corrosion resistance

The waterborne acrylic resin modified by both itaconic acid (IA) and γ-methacryloxypropyl triisopropoxidesilane (KH571) was successfully synthesized by the seeded emulsion polymerization. The effects of IA and KH571 on the properties of waterborne acrylic resin, including mechanical properties, water resistance, thermal stability, storage stability and corrosion resistance, were studied. Fourier transform infrared spectroscopy analysis showed that IA and KH571 were successfully copolymerized with acrylic monomers. Compared with the unmodified resin, the introduction of IA and KH571 greatly improved the water resistance of the resin coating. When 2 wt% IA and 4 wt% KH571 were added, the contact angle of the resin coating increased from 78.91° to 90.49°. The water resistance time of the resin coating was improved from one day to 17 days. Additionally, the modified resin showed better mechanical properties, thermal stability, storage stability and corrosion resistance. The waterborne acrylic resin modified with IA and KH571 has a potential application prospect in the fields of waterproof and anticorrosive coating