The concept of interfacial polymerization is utilized for the synthesis of polyaniline–phosphomolybdate (PAni–PMo12) molecular hybrids and it is well characterized. The electrical conductivity of the synthesized hybrid materials increases with increase in PMo12 wt%. The synthesized hybrid materials are evaluated as the active electrode materials for supercapacitor application. Cyclic voltammetric studies of the hybrid-modified electrode shows broad parallelogram-shaped peak as an evidence for pseudo-capacitive behaviour. The galvanostatic charge–discharge studies enlighten that interfacially synthesized hybrid materials loaded with PMo12 show relatively enhanced specific capacitance values than PMo12 free samples.

Multi-walled carbon nanotubes (MWCNTs) were decorated with palladium nanoparticles (Pd NPs) by laserablationof a physical mixture of MWCNTs and Pd NPs without using any reducing agent. The morphology and composition of MWCNT/Pd were analysed by complementary techniques involving Fourier transform infrared spectrometry,transmission electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. Using cyclic voltammetry and chronoamperometry, the electrocatalytic activity and stability of CNT/Pd were evaluated for the electrochemical oxidation of methanol in a basic medium. Comparative investigations were provided with laser-ablated Pd NPs (LA Pd) catalyst concerning catalytic activity and stability. MWCNT/Pd exhibited remarkably high catalytic activity (104.20 mA mg$^{-1}$) in comparison to the LA Pd catalyst (14.41 mA mg$^{-1}$). The catalyst was found to exhibit longterm stability even after 3600 s of operation and high resistance towards CO poisoning. It is suggested that the MWCNT/Pd would be valuable as an active electrocatalyst for its commercial applications in direct methanol fuel cells.

A hydrothermal approach was followed to make highly exfoliated MoS$_2$ nanosheets with hexamethylenetetramine as the exfoliating agent. The synthesized MoS$_2$ nanosheets have a petal-like structure, as evidenced by scanning electron microscopy and transmission electron microscopy. Using this MoS$_2$ nanosheet, various adsorption isotherm and kinetic models were studied to remove contaminants such as tartrazine dye and mercury in the aqueous solutions. The Freundlich isotherm model, which yields the best match, implicates the multilayer adsorption process. In this study, pseudo-first-order kinetics was found to be a good fit indicating the physisorption process for tartrazine dye adsorption and pseudo-second-order kinetics for mercury ion adsorption. Also, it was noticed that MoS$_2$ nanosheets had eliminated 99% of the tartrazine dye and mercury from the aqueous solution within 5 min and 6 h intervals of time, respectively. The maximal adsorption capabilities for tartrazine dye and mercury ions were 41 and 495 mg g$^{–1}$, respectively.