The replacement of noble-metal-based electrocatalysts with earth-abundant, low-cost bifunctional electrocatalysts for efficient hydrogen generation is required. Herein, an amorphous and porous 2D NiFeCo hydroxide nanosheets grown on nickel foam (NF) (NiFeCo LDH/NF) by a cost-effective electrodeposition method was explored for efficient electrolytic water splitting and urea electrolysis. Experimental results show that porous confinement in 2D orientation, amorphous nature, and synergistic effect leads to the excellent catalytical performance of the as-prepared 2D NiFeCo LDH/NF electrode for overall water splitting and urea electrolysis. The NiFeCo LDH/NF electrode presents promising behavior for water electrolysis with a small overpotential of 210 mV and 108 mV, respectively, is required for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) to gain 10 mA cm −2 . More notably, the bifunctional NiFeCo LDH/NF catalyst, for water electrolysis, needs a lower potential of 1.57 V to gain 10 mA cm −2 in 1 KOH. Furthermore, the electrochemical urea oxidation results show that NiFeCo LDH/NF requires just 0.280 V (vs SCE) to drive 10 mA cm −2 in 1 M KOH with a 0.33 M urea, whereas urea-mediated electrolysis cells require a very low potential of 1.49 V at 10 mA cm −2 . The present results provide remarkable and notable insights into the preparation of non-noble and highly efficient 2D transition metal hydroxide electrocatalysts with performances that allow them to compete for widespread use in various applications.

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The use of an appropriate delivery system capable of protecting, translocating, and selectively releasing therapeutic moieties to desired sites can promote the efficacy of an active compound. In this work, we have developed a nanoformulation which preserves its magnetization to load a model anticancerous drug and to explore the controlled release of the drug in a cancerous environment. For the preparation of the nanoformulation, self-assembled magnetic nanospheres (MNS) made of superparamagnetic iron oxide nanoparticles were grafted with a monolayer of (3-aminopropyl)triethoxysilane (APTES). A direct functionalization strategy was used to avoid the loss of the MNS magnetization. The successful preparation of the nanoformulation was validated by structural, microstructural, and magnetic investigations. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) were used to establish the presence of APTES on the MNS surface. The amine content quantified by a ninhydrin assay revealed the monolayer coverage of APTES over MNS. The monolayer coverage of APTES reduced only negligibly the saturation magnetization from 77 emu/g (for MNS) to 74 emu/g (for MNS-APTES). Detailed investigations of the thermoremanent magnetization were carried out to assess the superparamagnetism in the MNS. To make the nanoformulation pH-responsive, the anticancerous drug Nintedanib (NTD) was conjugated with MNS-APTES through the acid liable imine bond. At pH 5.5, which mimics a cancerous environment, a controlled release of 85% in 48 h was observed. On the other hand, prolonged release of NTD was found at physiological conditions (i.e., pH 7.4). In vitro cytotoxicity study showed dose-dependent activity of MNS-APTES-NTD for human lung cancer cells L-132. About 75% reduction in cellular viability for a 100 μg/mL concentration of nanoformulation was observed. The nanoformulation designed using MNS and monolayer coverage of APTES has potential in cancer therapy as well as in other nanobiological applications.

The main cause of the large open-circuit voltage (Voc)-deficit in kesterite-based thin-film solar cells (TFSCs) is the high concentration of defects, related defects clusters, and poor band tailing characteristics. We...