Search Results (3)

Dye-sensitized solar cells (DSSCs) have emerged as promising alternatives to traditional silicon photovoltaics owing to their environmentally friendly nature, easy preparation, and low cost. However, a critical bottleneck in DSSC fabrication lies in the high-temperature treatment required for the metal-oxide, primarily titanium dioxide (TiO₂), photoanode. This study presents an advanced approach aimed at overcoming this challenge by developing a facile and cost-effective room temperature processable TiO₂ paste for large-scale device production and commercialization. In our investigation, TiO₂ nanoparticles were synthesized using the sol-gel hydrothermal method. The resulting material served as the basis for a solar paint formulation, utilized as a precursor for the photoanode in tertiary butyl alcohol. Applying this paint, achieved with a simple paintbrush, eliminated the need for high-temperature curing, binders, and reduced chemical additives. This minimizes energy consumption during fabrication and enhances the interface quality and charge transport properties of the photoanode, as evidenced by photovoltaic impedance spectroscopy measurements. Full article

Li₄Ti₅O₁₂ (LTO) is a promising anode material for lithium-ion batteries (LIBs) due to its stable reversibility, high-rate cyclability, and high operational potential. On the other hand, it suffers from poor electronic conductivity and low capacitance. To overcome these disadvantages, modification of the LTO surface is frequently undertaken. Considering this idea, the production of a biomass-derived carbon-coated LTO material (LTO/C) and its application as an anode in LIBs is described in this work. The carbon precursor was obtained from commercial carrot juice, which was degraded using microwaves. According to the UV studies, the carbon precursor revealed similar properties to carbon quantum dots. Then, it was deposited on LTO synthetized through a sol-gel method. The LTO/C electrode exhibited a high specific capacity of 211 mAhg⁻¹ at 0.1 C. Capacity retention equal to 53% of the initial value was found for the charge–discharge rate increase from 0.1 C to 20 C. The excellent electrochemical performance of LTO/C was caused by the carbon coating, which provided (i) short diffusion pathways for the Li⁺ ions into the LTO structure and (ii) enhanced electronic conductivity. The obtained results indicated that biomass-derived carbon quantum dot-coated LTO can be considered as a promising anode for LIBs. Full article

The precursor for a lithium-ion sieve is prepared using an inorganic precipitation-peptization method with titanium sulfate as the titanium source and lithium acetate as the lithium source. The effects of Ni²⁺ (Nickel ions) doping on the stability of the sol, crystal morphology and interplanar spacing of Li₂TiO₃ are investigated. The results indicate that, after Ni²⁺ doping with varying fractions, the stability of the precursor sol first increases then decreases, and the maximum stabilization time of the precursor sol doped with 1% Ni²⁺ is 87 h. When doped with 1% Ni²⁺, the sol performance is most stable, the porous Li₂TiO₃ is obtained, and the specific surface area of Li₂TiO₃ increases by up to 1.349 m²/g from 0.911 m²/g. Accompanying the increase in calcination temperature, the inhibition of Ni²⁺ doping on the growth and crystallization of grains decreases. When the temperature is lower than 750 °C, Ni atoms replace the Ti atoms that are substituted for Li atoms in the original pure Li layer, forming lattice defects, resulting in the disappearance of (002) and (−131) diffraction peaks for Li₂TiO₃, the reduced ordering of crystal structure, a decrease in the interplanar spacing of the (002) plane, lattice expansion and an increase in the particle size to 100–200 nm. When the temperature exceeds 750 °C, with the increase of calcination temperature, the influence of Ni doping on the growth and crystallinity of grains decreases, and the (002) crystal surface starts to grow again. Full article