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In this study, CoFe2O4 and CoFe2O4/rGO samples were synthesized using co-precipitation and wet impregnation methods, respectively, and their sensing capabilities were assessed for ammonia gas detection at room temperature. The formation of the CoFe2O4/rGO nanocomposite was thoroughly examined through various analytical techniques, revealing its enhanced properties. Notably, the CoFe2O4/rGO nanocomposite exhibited significantly higher sensitivity compared to pure CoFe2O4, with a calculated sensitivity value of 1.098. The material also demonstrated rapid response and recovery times of 61 s and 143 s, respectively, for a 100-ppm ammonia gas concentration at room temperature. These findings highlight the potential of the CoFe2O4/rGO nanocomposite for efficient and sensitive gas sensing applications.

Abstract In recent years, there has been an increase in demand for inexpensive biowaste-derived photocatalysts for the degradation of hazardous dyes and pharmacological drugs. Here, we developed eggshell derived hydroxyapatite nanoparticles entrenched on two-dimensional g-C3N4 nanosheets. The structural, morphological and photophysical behavior of the materials is confirmed through various analytical techniques. The photocatalytic performance of the highly efficient HAp/gC3N4 photocatalyst is evaluated against methylene blue (MB) and doxycycline drug contaminates under UV–visible light exposure. The HAp/gC3N4 photocatalyst exhibit excellent photocatalytic performance for MB dye (93.69%) and doxycycline drug (83.08%) compared to bare HAp and g-C3N4 nanosheets. The ultimate point to note is that the HAp/gC3N4 photocatalyst was recycled in four consecutive cycles without any degradation performance. Superoxide radicals play an important role in degradation performance, which has been confirmed by scavenger experiments. Therefore, the biowaste-derived HAp combined with gC3N4 nanosheets is a promising photocatalyst for the degradation of hazardous dyes and pharmacological drug wastes.

We establish sufficient conditions for the existence of solutions of an integral boundary value problem for a Ψ-Hilfer fractional integro-differential equations with non-instantaneous impulsive conditions. The main results are proved with a suitable fixed point theorem. An example is given to interpret the theoretical results. In this way, we generalize recent interesting results.

We propose a solution to the symmetric nonlinear Ψ-Caputo fractional integro differential equations involving non-instantaneous impulsive boundary conditions. We investigate the existence and uniqueness of the solution for the proposed problem. Banach contraction theorem is employed to prove the uniqueness results, while Krasnoselkii’s fixed point technique is used to prove the existence results. Additionally, an example is used to explain the results. In this manner, our results represent generalized versions of some recent interesting contributions.