This study demonstrates the use of perovskite solar cells for fabrication of self-charging lithium-ion batteries (LIBs). A LiFePO₄ (LFP) cathode and Li₄Ti₅O₁₂ (LTO) anode were used to fabricate a LIB. The surface morphologies of the LiFePO₄ and Li₄Ti₅O₁₂ powders were examined using field emission scanning electron microscopy. The structural properties of the two powders were investigated using X-ray diffraction. The electrochemical properties of the LiFePO₄-Li and Li₄Ti₅O₁₂-Li half cells and of the full cell were investigated. The LiFePO₄-Li₄Ti₅O₁₂ full cell showed an excellent Coulombic efficiency of 99.3% after 100 cycles. CH₃NH₃PBI₃ (MAPbI₃) perovskite solar cells (PSCs) were fabricated using a spin coating technique. A single PSC showed a power conversion efficiency of 12.95%. In order to develop a self-charging system for LIBs, four single PSCs connected in series were used as an LFP-LTO battery. The integrated PSC system showed a power conversion efficiency of 12.44%. The PSC-LIB coupled device showed excellent overall self-charging conversion and a storage efficiency of 9.25%.

Detection of formaldehyde is very important in terms of life protection, as it can cause serious injury to eyes, skin, mouth and gastrointestinal function if indirectly inhaled. Researchers are therefore putting effort into developing novel and sensitive devices. In this work, we have fabricated an electro-chemical sensor in the form of a field effect transistor (FET) to detect formaldehyde over a wide range (10 nM to 1 mM). For this, ZnO nanosheets (NS) were first synthesized by hydrothermal method with in-situ deposition on cleaned SiO₂/Si (100) substrate. The synthesized materials were characterized for morphology and purity and surface area (31.718 m²/g). The developed device was tested for formaldehyde detection at room temperature that resulted in a linear (96%) and reproducible response with concentration, sensitivity value of 0.27 mA/M/cm² with an error of ±2% and limit of detection (LOD) as 210 nM.

In this work, the structural, optical, morphological, and sensing features of tungsten oxide (WO₃) thin film deposited on a silicon substrate via hot-filament chemical vapor deposition (HFCVD) are described. The experimental characterization tools, such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible (UV-Vis), and Fourier transform infra-red (FTIR) spectroscopies, etc., were used to determine the properties of WO₃ NPys thin films. The grown WO₃ thin film illustrated closely packed porous pyramidal nanostructures (NPys) of improved grain size properties. The diffraction analysis revealed (100) and (200) of WO₃ phases, suggesting the classic monoclinic crystal WO₃ structure. HFCVD grown WO₃ NPys thin film was employed as electro-active electrode for detecting ethylenediamine in 10 mL of 0.1 M phosphate buffer solution (PBS) by varying the ethylenediamine concentrations from 10 μM to 200 μM at room temperature. With a detection of limit (LOD) of ~9.56 μM, and a quick reaction time (10 s), the constructed chemical sensor achieved a high sensitivity of ~161.33 μA μM⁻¹ cm⁻². The durability test displayed an excellent stability of electrochemical sensor by maintaining over 90% sensitivity after 4 weeks of operation. This work provides a strategy for a facile preparation of WO₃ NPys thin film electrode for sensor applications.

A simple hydrothermal synthesis approach was used to synthesize porous MgNiO₂ Chrysanthemum Flowers (CFs) nanostructures and applied as a sensing electrode for quick detection of hazardous mercury (Hg²⁺ ions). The morphological, structural, and electrochemical properties of MgNiO₂ CFs were investigated. The morphological characteristic of MgNiO₂ CFs, with a specific surface area of 45.618 m²/g, demonstrated strong electrochemical characteristics, including cations in different oxidation states of Ni³⁺/Ni²⁺. Using a three-electrode system for electrochemical detection, the MgNiO₂ CFs based electrode revealed a good correlation coefficient (R²) of ~0.9721, a limit of detection (LOD) of ~11.7 μM, a quick response time (10 s), and a sensitivity of 8.22 μA∙μM⁻¹∙cm⁻² for Hg²⁺ ions over a broad linear range of 10–100 μM. Moreover, the selectivity for Hg²⁺ ions in tap water and drinking water was determined, and a promising stability of 25 days by MgNiO² CFs electrode was exhibited. The obtained results indicate that the developed MgNiO₂ CFs are a promising electrode for detecting hazardous Hg²⁺ ions in water and have the potential to be commercialized in the future.