Optimization of organic meso-superstructured solar cells for underwater IoT² self-powered sensors

The effectiveness of the mesoporous TiO₂ layer, which acts as an active n-type semiconductor layer in dye-sensitized solar cells (DSSCs), was investigated by varying AgVO₃ doping. To optimize the meso-superstructure, the doping concentration was varied from 0% to 25% using experimentally validated simulations. Moreover, performance comparisons between the experimentally fabricated DSSCs based on natural beetroot dye and the commonly used N719 dye were made. A 15% doping concentration was found optimum for our DSSC, which delivered an output power of 19.24 mW, 6.1% power conversion efficiency, and an open-circuit voltage, Voc , of 0.5 V and a short-circuit current density, Jsc , of 21 mA/cm² in diffused light conditions. Based on these performance results, we integrated our optimized DSSC in an underwater sensing unit as a light harvester

Synthesis and characterization of novel magnetic nanoparticles for photocatalytic degradation of indigo carmine dye

A successful photo degradation of indigo carmine dye was carried out on magnetic SnO2 nanoparticles synthesized by control sol–gel route using triton-x100 as structure and pore directing agent. CoFe2O4 nanoparticles were successfully incorporated with high precision SnO2 surface through sonochemical route. The physicochemical characteristics and properties of the nanoparticles that were prepared were investigated by [DRS] diffuse reflectance spectra, [FESEM] field emission scanning electron microscope, photoluminescence, energy dispersive X-ray [EDX] and [XRD] X-ray diffraction. Various proportions of CoFe2O4 as promising magnetite were incorporated on the surface of tin oxide by ultrasonic route for shifting the photo-catalytic response to visible region and facilitating the collection of the solid catalyst after the degradation process. The results showed that the band gap energy calculated for SnO2 and COFe2O4/SnO2 are 3.32 and 2.88 eV, respectively confirming the positive role of the magnetic nanoparticles in this shift. The research obtained that the crystalline size calculated by the Scherrer's equation is about 43 and 13 nm for bare SnO2 and COFe2O4/SnO2 nanoparticles. Besides, the EDX test showed the presence of constituents of cobalt (CO), oxygen (O), ferric oxide (Fe2O3), tin (Sn) and small negligible traces of chlorine (Cl) in the prepared nanoparticle. The photocatalytic reactivity reaches 55% on SnO2 surface. However, incorporation of CoFe2O4 nanoparticles enhance the magnetic properties of the photo catalyst on the expense of the removal efficiency. The results indicate that the magnetic nanoparticles with sphere-like structure can be a good candidate for removal of IC dye from wastewater

Adsorption of polluted dyes from water by transition metal oxides: A review

Water is the source of life on the planet's surface. Water safety has become a crucial requirement for safe drinking water as a result of the increase in activities that can pollute water supplies. Every year, thousands of tons of dyes used in industry are discharged into water. The health and environmental issues brought on by dye pollution make surface water contamination a global issue of the utmost concern. Removal of dyes by adsorption technology is a particularly important technique, because of its usability, simplicity, high efficiency, and scale-up over a wide range of concentrations. Metal oxides are considered among the widely used nanomaterials for environmental control and contaminations removal. Such properties come from their variable oxidation states, large surfaces, and varying electronic configurations. This review focuses on the use of metal oxides in pure form, especially those of the first transition series for the treatment of wastewater from various kinds of organic dyes. Experimental studies were searching for efficient removal of dyes, and providing the suitable removal conditions besides the mechanism of adsorption through the isothermal and kinetic studies

Boosting dye-sensitized solar cell efficiency using AgVO3-doped TiO2 active layer

Dye-sensitized solar cells have shown great potential in low and self-powered nano/micro-scale applications, due to their low fabrication costs, semi-transparency in the visible spectrum, diffused light harvesting capabilities, and their lead-free structure. However, DSSC efficiencies are still relatively low due to their limited absorption capabilities in the active mesoporous layer. The current study demonstrates an attempt to boost the overall conversion efficiency of DSSC by narrowing the energy band gap of the mesoporous TiO2 active layer. AgVO3 is utilized in doping the mesoporous layer, seeking for a visible absorption shift from 3.2 eV to 2.6 eV. In addition, natural organic beetroot dye is used while keeping DSSC with N719 dye as a bare cell. Morphological, optical, as well as electrical characterization results were obtained for both thin-film and complete solar cells. The fabricated cell showed an overall harvested power density of 8.6 mW/cm2, capable of operating various low-power sensing applications

Two-Dimensional MXene as a Promising Adsorbent for Trihalomethanes Removal: A Density-Functional Theory Study

This groundbreaking research delves into the intricate molecular interactions between MXene and trihalomethanes (THs) through a comprehensive theoretical study employing density-functional theory (DFT). Trihalomethanes are common carcinogenic chlorination byproducts found in water sanitation systems. This study focuses on a pristine MXene [Mn+1·Xn] monolayer and its various terminal [Tx] functional groups [Mn+1·XnTx], strategically placed on the surface for enhanced performance. Our investigation involves a detailed analysis of the adsorption energies of THs on different MXene types, with the MXene-Cl layer emerging as the most compatible variant. This specific MXene-Cl layer exhibits remarkable properties, including a total dipole moment (TDM) of 12.443 Debye and a bandgap of 0.570 eV, achieved through meticulous geometry optimization and computational techniques. Notably, THs such as trichloromethane (CHCl3), bromide-chloromethane (CHBrCl2), and dibromochloromethane (CHBr2Cl) demonstrate the highest TDM values, indicating substantial changes in electronic and optical parameters, with TDM values of 16.363, 15.998, and 16.017 Debye, respectively. These findings highlight the potential of the MXene-Cl layer as an effective adsorbent and detector for CHF3, CHClF2, CHCl3, CHBrCl2, and CHBr2Cl. Additionally, we observe a proportional increase in the TDM and bandgap energy, indicative of conductivity, for various termination atom combinations, such as Mxene-O-OH, Mxene-O-F, Mxene-O-Cl, Mxene-OH-F, Mxene-F-Cl, and Mxene-OH-Cl, with bandgap energies measured at 0.734, 0.940, 1.120, 0.835, and 0.927 eV, respectively. Utilizing DFT, we elucidate the adsorption energies of THs on different MXene surfaces. Our results conclusively demonstrate the significant influence of the termination atom nature and quantity on MXene’s primitive TDM value. This research contributes to our understanding of MXene–THs interactions, offering promising avenues for the development of efficient adsorbents and detectors for THs. Ultimately, these advancements hold the potential to revolutionize water sanitation practices and enhance environmental safety