Realisation of CdS/Mn3O4nanocomposites for potential Photocatalytic Applications

The present work reports the realisation of high-quality crystalline CdS/Mn3O4(CM) nanocomposites by a simple cost-effective chemical method in air atmosphere. The authors have performed theoretical calculations and experimental analysis in order to understand the synthesised nanocomposites. X-ray diffraction results showed that the CM nanocomposites were cubic and orthorhombic mixed structure which is in good agreement with the theoretical studies. Field emission scanning electron microscopy images of CM confirmed the formation of well distributed nanocomposites. The outcomes of DFT calculations provide results for the bandgap calculation of pure CdS, Mn3O4and the CM nanocomposites. Photoluminescence studies with interesting visible light absorption demonstrated the great potentiality of the as-synthesised nanocomposites towards photocatalytic applications that could be a detailed research scope for the authors' future studies. © 2020 Institution of Engineering and Technology. All rights reserved.Acknowledgments: The author P. Joice Sophia kindly acknowledges DST-INSPIRE Faculty Scheme (DST/INSPIRE/04/2016/ 000292) and SERB-EMR (EMR/2017/004764) for the financial support and funding. One of the authors, M. Rajesh Kumar thanks the contract no. 40/is2

Realization of Ti MOF/MoS2 Hybrid Nanostructure and Their Catalytic Activity Towards 4-Nitrophenol Reduction

The development of effective catalysts for catalytic reduction of the toxic 4-Nitrophenol (4-NP) into useful 4-Aminophenol (4-AP) has received wide interest. Herein, we report the synthesis of Titanium Metal–Organic Framework (Ti-MOF)/MoS2 hybrid nanostructure as potential catalyst for the reduction of 4-NP. Various characterization tools such as FESEM, TEM, XRD, and XPS have been used to conduct the morphological and structural analysis of the hybrid nano catalyst. The catalytic studies suggest that the as-prepared Ti-MOF, MoS2, and Ti-MOF/MoS2 hybrid nanostructures effectively catalyze the reduction of 4-NP to 4-AP in the presence of NaBH4. The rate constant (Kapp) of MOF/MoS2 hybrid nanostructure is found to be 1.208 min−1, which proves its higher catalytic performance in comparison with the pristine samples. Additionally, its preeminent reusability performance makes MOF/MoS2 hybrid nanostructure to be used as effective and practical catalyst. Through this work, the potential for the heterostructure's high catalytic activity is conversed and a possible reaction mechanism is proposed. Our findings confirm that the hybrid MOF@MoS2 nanoflakes have provided a promising interface for the hydrogenation procedure on the catalytic surface, thereby making it an excellent catalytic material to be further investigated. © 2022 The Authors.The authors greatly acknowledge the Photonics Research facility of Aaivalayam-DIRAC, Coimbatore, India for the funding and laboratory support. One of the authors (Manavalan Rajesh Kumar) thanks to the contract no. 40/is2

Fingerprints for Structural Defects in Poly(thienylene vinylene) (PTV): A Joint Theoretical–Experimental NMR Study on Model Molecules

In the field of plastic electronics, low band gap conjugated polymers like poly(thienylene vinylene) (PTV) and its derivatives are a promising class of materials that can be obtained with high molecular weight via the so-called dithiocarbamate precursor route. We have performed a joint experimental- theoretical study of the full NMR chemical shift assignment in a series of thiophene-based model compounds, which aims at (i) benchmarking the quantum-chemical calculations against experiments, (ii) identifying the signature of possible structural defects that can appear during the polymerization of PTV's, namely head-to-head and tail-to-tail defects, and (iii) defining a criterion regarding regioregularity

Form tolerances investigation in EDM process for super alloys using multiple holes electrodes

200-204The present work focuses on experimental quality analysis of electrical discharge machining (EDM) of two super alloys namely Inconel 718 and Inconel 625 with different diameter of hole of multiple holes copper electrodes. The diameter of hole of multiple holes in electrode, pulse current and (Ton) pulse on time have been chosen as process parameters to conduct the experiment trails. The MRR, EWR and form tolerance have been considered as output responses

Optimization of machining parameters of EDM while machining Inconel 718 for form tolerance and orientation tolerance

391-397This paper demonstrates the effectiveness of optimizing multiple characteristics of electrical discharge machining (EDM) of Inconel 718 using copper electrodes having different shapes via Taguchi method-based Grey analysis. The modified algorithm adopted here is used successfully for both detraining the optimum settings of machining parameters and for combining multiple quality characteristic into one numerical value called Grey relational grade or rank. The essential parameters like peak current, pulse on time and pulse off time are chosen to conduct the experiments on multiple characteristics namely material removal rate (MRR), electrode wear rate (EWR), form tolerance namely straightness and orientation tolerance like perpendicularity and angularity. Then, ANOVA is used to find out the parameter which significantly affects the other parameters. The experimental results have shown that the machining performance on multiple characteristics in the EDM process is improved effectively through this approach

EXPERIMENTAL INVESTIGATION ON ELECTRICAL DISCHARGE MACHINING OF TITANIUM ALLOY USING COPPER, BRASS AND ALUMINUM ELECTRODES

In the present study, an evaluation has been done on Material Removal Rate (MRR), Surface Roughness (SR) and Electrode Wear Rate (EWR) during Electrical Discharge Machining (EDM) of titanium alloy using copper, brass and aluminum electrodes. Analyzing previous work in this field, it is found that electrode wear and material removal rate increases with an increase current. It is also found that the electrode wear ratio increases with an increase in current. The higher wear ratio is found during machining of titanium alloy using a brass electrode. An attempt has been made to correlate the thermal conductivity and melting point of electrode with the MRR and electrode wear. The MRR is found to be high while machining titanium alloy using brass electrode. During machining of titanium alloy using copper electrodes, a comparatively smaller quantity of heat is absorbed by the work material due to low thermal conductivity. Due to the above reason, the MRR becomes very low. Duringmachining of titanium alloy using aluminium electrodes, the material removal rate and electrode wear rate are only average value while machining of titanium alloy using brass and copper electrodes

Synthesis and Thermal Adsorption Characteristics of Silver-Based Hybrid Nanocomposites for Automotive Friction Material Application

Advances in friction materials are imposed on developing multiceramic reinforced hybrid nanocomposites with superior tribomechanical properties. The silver-based matrix metals are gained significance in various applications like bearing, ratchet, and electrical contacts due to their high frictional resistance and good thermal and chemical stability compared to traditional metals. The present research is to develop silver-based hybrid nanocomposites containing alumina (Al2O3) and silicon carbide (SiC) nanoparticles of 50 nm mixing with the ratio of 0 wt% Al2O3/0 wt% SiC, 5 wt% Al2O3/0 wt% SiC, and 5 wt% Al2O3/5 wt% SiC via the semisolid vacuum stir-cast technique. The vacuum technology minimizes casting defects and increases composite properties. The casted composite samples are subjected to study the effect of reinforcement on thermal adsorption, conductivity, diffusivity, and frictional resistance. The composite containing 5 wt% Al2O3np/5 wt% SiCnp is to find optimum thermal and frictional behaviour. The thermal adsorption and frictional resistance are increased by 30% and 27% compared to unreinforced cast silver. The Ag/5 wt% Al2O3np/5 wt% SiCnp hybrid nanocomposite is recommended for automotive friction-bearing applications