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In this article, the impact of the loading of CdS between Pt and 3D graphene was investigated determining enhanced visible light absorption and efficient charge separation at the interfaces that have improved methanol oxidation reaction activities. The structural, morphological, optical and electrochemical properties of photoanodes were investigated. The highest current density reached 264 mA cm−2 at 0.28 V vs. Ag/AgCl under one sun illumination for Pt/10-CdS/3D-Gr@Ni-Foam as compared to 116 mA cm−2 at 0.26 V for Ag/AgCl in the dark at a scan rate of 10 mV s−1. The diffusion coefficient of electron transfer is also enhanced to 3.99 × 10−3 cm2 s−1 under illumination as compared to 2.971 × 10−3 cm2 s−1 under dark conditions for the Pt/10-CdS/3D-Gr@Ni-Foam heterostructure. The decrease in the charge transfer resistance (Rct) from 34.31 Ω to 2.38 Ω indicated that the introduction of CdS enhanced the separation and transportation of photoexcited charges and also improved the kinetics of the electron transfer reaction. The Pt/10-CdS/3D-Gr@Ni-Foam exhibited a significantly enhanced net donor density (ND) of 2.5 × 1020, surpassing the donor density of 1.5 × 1020 of the Pt/3D-Gr@Ni-Foam. Both Pt and 3D-graphene are being utilized as a well, for efficient charge separation and transportation at either side of the CdS sandwich, resulting in effective transfer of charges at the corresponding Pt/CdS/3D-Gr@Ni-Foam heterostructure interfaces and increased electron density on Pt showed its unprecedented potential to be utilized for electrocatalytic and photo-electrocatalytic applications. [ABSTRACT FROM AUTHOR]

This work explores the characteristics of two-dimensional (2D) titanium carbide (Ti3C2 MXene) and utilizes first-principles study to weigh its potential for supercapacitor applications. Scanning electron microscopy images confirm the layered morphology of the MXene, and energy-dispersive X-ray spectroscopy (EDX) analysis supports the extraction of aluminum from the MAX phase. Fourier-transform infrared (FTIR) spectroscopy confirms the presence of oxygen-based functional groups on the surface of the MXene and X-ray diffraction (XRD) patterns validate its hexagonal crystalline structure. Cyclic voltammetry (CV) analysis reveals the presence of redox peaks, indicating the pseudocapacitive behaviour of the fabricated electrode. Additionally, galvanostatic charge–discharge (GCD) measurements yield a calculated specific capacitance of 370 F g−1. Electrochemical impedance spectroscopy (EIS) substantiates the low impedance resulting from the layered structure via the adequate adsorption/desorption of cations. The utilization of first-principles density functional theory (DFT) calculations reveals the merging of conduction and valence bands, signifying effective conductivity. Both the total and partial density of states cross the Fermi level, indicating a highly efficient charge mobility process. The combination of prominent surface redox reactions and excellent conductivity contributes to the superior specific capacitance of the fabricated electrode. Overall, these results highlight the excellent electrochemical properties of the Ti3C2 MXene electrode, declaring it as a promising candidate for supercapacitor applications. [ABSTRACT FROM AUTHOR]