Efficient photocatalytic degradation of Rhodamine B catalyzed by SrFe2O4/g-C3N4 composite under visible light

Low-Cost Inorganic Strontium Ferrite a Novel Hole Transporting Material for Efficient Perovskite Solar Cells

Perovskite solar cells attract significant interest due to their high-power conversion efficiencies. The replacement of charge-transporting layers using inorganic materials is an effective approach for improving stability and performance, as these materials are low-cost, highly durable, and environmentally friendly. This work focuses on the inorganic hole and electron transport layers (HTL and ETL), strontium ferrite (SrFe2O4), and zinc oxide (ZnO), respectively, to enhance the efficiency of perovskite solar cells. Favorable band alignment and high charge-collection capability make these materials promising. Experimental and computational studies revealed that the power conversion efficiency of the fabricated device is 7.80% and 8.83%, respectively. Investigating electronic properties and interface charge transfer through density functional theory calculations further corroborated that SrFe2O4 is a good HTL candidate. Our numerical device modeling reveals the importance of optimizing the thickness (100 nm and 300 nm) of the HTL and perovskite layers and defect density (1016 cm−3) of the absorber to achieve better solar cell performance.

Insight in to sunlight-driven rapid photocatalytic degradation of organic dyes by hexacyanoferrate-based nanoparticles

Release of colouring agents into the environment alarms the need to design a cheap, quick and safe process. Owing to environmental safety concern, synthesis of two metal hexacyanoferrates (MHCFs) based on cadmium (CdHCF) and manganese (MnHCF) was carried out using natural plant extract of Azadirachta indica and water as a solvent. Synthesized MHCFs were utilized for the removal of an acid dye (fuchsin acid, FA) and a xanthenes dye (rhodamine B, RB). The reactions were optimized at various conditions of dye concentration, catalyst dose, reaction pH, time and source of light. The MHCFs showed excellent results with both the dyes within very limited span of time (2 h). Consequently, 98% of FA and 97% of RB were degraded with 10 mg of CdHCF, at neutral pH and under sunlight. The degradation process followed the first-order reaction kinetics having t_1/2 around 0.3 min. The MHCFs exhibited difference of only little percentage in degradation owing to a very slight difference between their surface areas (CdHCF: 54.1 m² g^-1; MnHCF: 49.7 m² g^-1). The synthesised nanocatalysts were stable as indicated by their higher negative zeta potential values. The adsorption of dyes was found to be maximum with CdHCF having X_m value 19.69 mg g^-1 and 18.15 mg g^-1 for FA and RB, respectively. Photocatalytic degradation involved the main role of hydroxyl radical as indicated by decline in activity of nanocatalyst in the presence of scavengers. All in all, this study presents highly active nanomaterials with higher surface area, stability and semiconducting properties under natural conditions.

Exploring different photocatalytic behaviors of CdxZn1−xSeyS1−y gradient-alloyed quantum dots via composition regulation

Different photocatalytic behaviors of CdxZn1−xSeyS1−y gradient alloyed quantum dots via composition regulation.

Efficient photocatalytic degradation of malachite green dye using facilely synthesized hematite nanoparticles from Egyptian insecticide cans

In the present study, a combustion method was applied for the production of hematite nanoparticles from Egyptian iron waste using l-arginine (The sample was named HA) and glutamine (The sample was named HG) as organic fuels, respectively. XRD confirmed that the HA and HG products have crystallite sizes of 48 and 56 nm, respectively. Also, HR-TEM demonstrated that spherical and irregular shapes have an average diameter of 45 and 59  nm were observed in the HA and HG samples, respectively. Besides, FE-SEM elucidated that spherical and irregular shapes have an average size of 142 and 196 nm were observed in the HA and HG samples, respectively. In addition, FT-IR confirmed that the peaks which were detected at 518 and 430 cm^-1 are because of vibrations of Fe-O bond. Moreover, the value of the energy gap for the HA and HG samples was 1.00 and 1.45 eV, respectively. Furthermore, the PL emission spectra elucidated that the emission intensity of the HA sample was less than that of the HG sample. So, e^-/h⁺ recombination rate of the HA sample was less than that of the HG sample. Hence, the photocatalytic degradation of malachite green dye using the HA sample was larger than that using the HG sample. In the absence of H₂O₂, the % degradation of malachite green dye under the influence of UV using HA and HG samples was 46.29 and 39.72 % after 3 h, respectively. Also, in the presence of H₂O₂, the % degradation of malachite green dye under the influence of UV using HA and HG samples was 100 % after 60 and 70 min, respectively.