A New CuSe-TiO2-GO Ternary Nanocomposite: Realizing a High Capacitance and Voltage for an Advanced Hybrid Supercapacitor

A high capacitance and widened voltage frames for an aqueous supercapacitor system are challenging to realize simultaneously in an aqueous medium. The severe water splitting seriously restricts the narrow voltage of the aqueous electrolyte beyond 2 V. To overcome this limitation, herein, we proposed the facile wet-chemical synthesis of a new CuSe-TiO2-GO ternary nanocomposite for hybrid supercapacitors, thus boosting the specific energy up to some maximum extent. The capacitive charge storage mechanism of the CuSe-TiO2-GO ternary nanocomposite electrode was tested in an aqueous solution with 3 M KOH as the electrolyte in a three-cell mode assembly. The voltammogram analysis manifests good reversibility and a remarkable capacitive response at various currents and sweep rates, with a durable rate capability. At the same time, the discharge/charge platforms realize the most significant capacitance and a capacity of 920 F/g (153 mAh/g), supported by the impedance analysis with minimal resistances, ensuring the supply of electrolyte ion diffusion to the active host electrode interface. The built 2 V CuSe-TiO2-GO||AC-GO||KOH hybrid supercapacitor accomplished a significant capacitance of 175 F/g, high specific energy of 36 Wh/kg, superior specific power of 4781 W/kg, and extraordinary stability of 91.3% retention relative to the stable cycling performance. These merits pave a new way to build other ternary nanocomposites to achieve superior performance for energy storage devices

Synergistic energy system [Sm³⁺-Eu³⁺-Tm³⁺]:CsPbI<inf>2.4</inf>Br<inf>0.6</inf> designing and thermal optimization for photovoltaic and electrical applications

Current work, for the first time elucidates the fabrication and energy applications of the novel perovskite hetero-system formed by the ternary lanthanide doping of CsPbI2.4Br0.6 leading to formation of [Sm3+-Eu3+-Tm3+]:CsPbI2.4Br0.6 (SET:CPVSK). SET:PVSK was tailored for the band gap spanning over the range of 1.59–1.66 eV over the course of 28 days, exhibiting excellent stability. With the cubic crystalline geometry, the spin coated thin films expressed maximum coverage and profound binding to substrate. As a perovskite light absorber, SET:CVSK based solar cell gained an efficiency of 17 % with the 68.92 % of fill factor and an expanded open circuit voltage (Voc) of 1.08 V. As an electro-catalyst, SET:CPVSK expressed moderate oxygen generation. While it demonstrated magnanimous pure hydrogen generation showing impressively minimal overpotential and Tafel slope value of 142 mV and 122.7 mV dec−1, respectively. With an extended service life in the electrolyte medium, SET:CPVSK adorned nickel foam electrode was marked by superior unit capacity of 661.24 mAH g−1 while the equivalent series resistance (Rs) i.e. 0.67 Ω, which shows the minimal resistance and facilitated diffusion of ions

[Gd³⁺-Ho³⁺-Dy³⁺]:CsPbI<inf>2.4</inf>Br<inf>0.6</inf>: Synergism between thermal optimization and lanthanide doping for enriched photoelectrical and electrochemical contraptions

This investigation, for the first time, reports the designing and application of the novel [Gd3+-Ho3+-Dy3+]:CsPbI2.4Br0.6 (GHD:CPVSK) heterostructure developed via tri-lanthanide doping route. For the prolonged duration of 28 days, GHD:CPVSK retained its optical output with the band gap energy spanning around 1.64–1.69 eV. The spin coated thin films were characterized with cubic phase and smoother morphology. As light harvester layer inside perovskite solar cell, GHD:CPVSK reached an efficiency of 16.73 % and an expanded open circuit voltage (Voc) of 1.1 V. GHD:CPVSK is a bifunctional electro-catalyst which has moderate oxygen generation activity while the pure hydrogen production activity was remarkable with the HER overpotential (ηHER) and Tafel slope value of 136 mV and 118.1 mV dec−1, respectively. In terms of the charge storage activity, the designed nickel foam electrode decorated with the GHD:CPVSK attained multi-step redox activity with the unit capacity of 555.24 mAH g−1 showing the excellency of this material in storing of charge. Furthermore, this electrode has remarkably minimal equivalent series resistance (Rs) i.e. 0.67 Ω which indicates the favorability of the facilitated diffusion of the charges on the interface between GHD:CsPbI2.4Br0.6 perovskite semiconductor electrode and NaCl electrolyte

Gearing towards the sustainable energy transformation, production, and storage using thermic modulated [Ce3+-Pr3+-Nd3+]:CsPbI2.7Br0.3 perovskite hetero-system

Current investigation elucidates the first report on the designing, optimization, and applications of the lanthanide tri-doped CsPbI2.7Br0.3 establishing [Ce3+-Pr3+-Nd3+]:CsPbI2.7Br0.3 (CPN:CPVSK). This novel heterostructure remained optically active for 28 days with the narrowed band gap ranging between 1.65 and 1.7 eV. CPN:CPVSK was identified with the cubic phase and average crystallite size was 58.92 nm. The spin coated thin films were marked by excellent compactness and maximal covering. As photo-converter inside an entirely air-processed perovskite solar cell, CPN:CPVSK attained the efficiency of 17.92 % and 1.1 V of the open circuit voltage (Voc). CPN-CPVSK decked nickel foam electrode expressed moderate affinity towards production of oxygen while the pure hydrogen generation activity was remarkable with the overpotential and kinetic Tafel slope value of 143.1 mV and 119.7 mV dec−1, respectively. With an impressive electrochemical service life, this electrode was also characterized with the commendable charge storage with the unit capacity of 567 mAH g−1 and a negligible equivalent series resistance (Rs) i.e. 0.51 Ω. CPN:CPVSK is a sustainable and energy efficient choice which has prospects for use in the energy systems at practical scale for maximizing the efficiency and stability

Process optimization study on the feedstock derived from Cerbera odollam seeds

Biodiesel, made from inedible oils, presents an intriguing eco-friendly option for diesel engines due to its comparable qualities with traditional diesel fuel, requiring no engine modifications. This work explores the possibility of using Cerbera odollam (sea mango) oil as a biodiesel feedstock. Cerbera odollam oil is readily available in many forested areas worldwide. However, before alkaline catalytic esterification, the FFA in the oil needs to be transformed into esters through catalytic acid esterification. Optimization of reaction parameters for biodiesel production, such as reaction time (2 h), reaction temperature (55 °C), catalyst concentration (1.2 wt%), and the molar ratio (5.5:1), has been tuned. The parameters of the biodiesel produced were comparable to typical biodiesel standards. The optimized reaction parameters significantly influenced the biodiesel yield and quality. Under optimal conditions, 94.5% of Cerbera odollam oil is converted into biodiesel. Non-edible oil from Cerbera odollam has likely to be a feasible substitute for diesel fuel in the form of biodiesel

The Effect of Structural Phase Transitions on Electronic and Optical Properties of CsPbI3 Pure Inorganic Perovskites

Hybrid inorganic perovskites (HIPs) have been developed in recent years as new high-efficiency semiconductors with a wide range of uses in various optoelectronic applications such as solar cells and light-emitting diodes (LEDs). In this work, we used a first-principles theoretical study to investigate the effects of phase transition on the electronic and optical properties of CsPbI3 pure inorganic perovskites. The results showed that at temperatures over 300 °C, the structure of CsPbI3 exhibits a cube phase (pm3m) with no tilt of PbI6 octahedra (distortion index = 0 and bond angle variance = 0). As the temperature decreases (approximately to room temperature), the PbI6 octahedra is tilted, and the distortion index and bond angle variance increase. Around room temperature, the CsPbI3 structure enters an orthorhombic phase with two tilts PbI6 octahedra. It was found that changing the halogens in all structures reduces the volume of PbI6 octahedra. The tilted PbI6 octahedra causes the distribution of interactions to vary drastically, which leads to a change in band gap energy. This is the main reason for the red and blue shifts in the absorption spectrum of CsPbI3. In general, it can be said that the origin of all changes in the structural, electronic, and optical properties of HIPs is the changes in the volume, orientation, and distortion index of PbI6 octahedra

A New CuSe-TiO2-GO Ternary Nanocomposite: Realizing a High Capacitance and Voltage for an Advanced Hybrid Supercapacitor

A high capacitance and widened voltage frames for an aqueous supercapacitor system are challenging to realize simultaneously in an aqueous medium. The severe water splitting seriously restricts the narrow voltage of the aqueous electrolyte beyond 2 V. To overcome this limitation, herein, we proposed the facile wet-chemical synthesis of a new CuSe-TiO2-GO ternary nanocomposite for hybrid supercapacitors, thus boosting the specific energy up to some maximum extent. The capacitive charge storage mechanism of the CuSe-TiO2-GO ternary nanocomposite electrode was tested in an aqueous solution with 3 M KOH as the electrolyte in a three-cell mode assembly. The voltammogram analysis manifests good reversibility and a remarkable capacitive response at various currents and sweep rates, with a durable rate capability. At the same time, the discharge/charge platforms realize the most significant capacitance and a capacity of 920 F/g (153 mAh/g), supported by the impedance analysis with minimal resistances, ensuring the supply of electrolyte ion diffusion to the active host electrode interface. The built 2 V CuSe-TiO2-GO||AC-GO||KOH hybrid supercapacitor accomplished a significant capacitance of 175 F/g, high specific energy of 36 Wh/kg, superior specific power of 4781 W/kg, and extraordinary stability of 91.3% retention relative to the stable cycling performance. These merits pave a new way to build other ternary nanocomposites to achieve superior performance for energy storage devices