Development of an easy sustainable synthetic pathway towards oxide nanomaterials (NMs) is a necessary challenge for nanotechnology research workers. Additionally, antimicrobial activity of oxide nanoparticles against multi drug resistance pathogenic bacteria motivates scientists to focus their research on oxide materials. We report here a cost effective, simple and eco-friendly pathway of synthesizing NiO nanoparticles (NPs). X-ray diffraction and energy dispersive X-ray study confirmed their crystallinity and composition. Field emission scanning electron microscope (FESEM) was employed to understand their surface architecture and the dimension of synthesized NiO NPs were found to be 20–30 nm from transmission electron microscope (TEM) study. The as synthesized NiO demonstrated typical spin glass behaviour which is one advantage of our synthetic procedure. Antimicrobial properties of NiO NPs were investigated using Gram negative and Gram positive bacteria and their bactericidal effects were determined from minimum inhibitory concentrations (MIC) and Minimum bactericidal concentrations (MBC). Haemolytic activity revealed the nontoxic nature of the NPs towards the blood proteins at MBC. TEM images of bacteria cells treated with NiO NPs showed irreversible damages to the cell wall leading to cell death. In light of our findings a possible mechanism of the antimicrobial effect of NiO NPs has been proposed.

Metal halide perovskites having high defect tolerance, high absorption characteristics, and high carrier mobility demonstrate great promise as potential light harvesters in photovoltaics and optoelectronics and have experienced an unprecedented development since their occurrence in 2009. Semiconductor quantum dots (QDs), on the other hand, have also been proved to be very flexible toward shape, dimension, bandgap, and optical properties for constructing optoelectronic devices. Of late, a strategic combination of both materials has demonstrated extraordinary promise in photovoltaic applications and optoelectronic devices. Combining QDs and perovskites has proved to be quite an effective strategy toward the formation of pinhole‐free and more stable perovskite crystals along with tunability of other properties. To boost this exciting research field, it is imperative to summarize the work done so far in recent years to provide an intriguing insight. This review is a critical account of the advanced strategy toward combining these two fascinating materials, including their different synthetic approaches regarding heteroepitaxial growth of perovskite crystals on QDs, carrier dynamics at the interface and potential application in the field of solar cells, light emitting diodes, and photodetectors.

The present work provides an effective methodology for controlled room-temperature aqueous synthesis of nickel oxalate (NiOX) nanosheets and nanoflakes in the presence of anion rich self-assembled bilayers of catanionic surfactant comprising of anionic sodium dodecyl sulfate (SDS) and cationic cetyltrimethylammonium bromide (CTAB). Encouragingly alteration of the CTAB/SDS ratio played an extraordinary role to form nanoflakes and nanosheets of NiOX. Our synthetic approach is combined with calcination to produce antiferromagnetic spherical and hexagonal nickel oxide (NiO) nanoparticles (NPs) as the end product. Synthesized nanostructured NiOX and NiO were characterized by X-ray diffraction study (XRD), energy dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). TEM studies illustrated that spherical NiO NPs have an average size around 5–10 nm and that of hexagonal NiO NPs have average width of about 22–27 nm. Temperature and field dependent magnetic properties of spherical and hexagonal NiO nanomaterials (NMs) were measured by using a SQUID magnetometer which revealed canted antiferromagnetic and spin glass nature, respectively. In addition, we report photocatalytic activity of NiO NMs, investigated on the photodegradation of phenol under ambient conditions, and as expected, the NiO having largest surface area showed best catalytic efficiency. This biomimetic catanionic surfactant inspired approach which require only metal ions as reactants have a definite potential towards an alternative, simple way of synthesizing metal oxide NMs.