Morphology control of nickel oxalate by soft chemistry and conversion to nickel oxide for application in photocatalysis

Abstract

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.

Ultrathin mesoporous NiO nanosheet-anchored 3D nickel foam as an advanced electrode for supercapacitors

“…NiO will be oxidated to NiOOH in charging, while reversible reactions will occur during discharging. 45 TEM was utilized to further characterize the ultrathin structure of NiO nanosheets supported on the 3D nickel foam. From the enlarged views (Figure 1b,c), the nanosheets of the nickel oxalate have an ultrathin structure with a thickness of less than 10 nm, and interconnect with each other to form clusters.…”

Influence of Pamoic Acid as a Complexing Agent in the Thermal Preparation of NiO Nanoparticles: Application to Electrochemical Water Oxidation

“…Among the mentioned methods, the latest one is well known as scalable with high yield. To prepare NiONPs, thermal decomposition of nickel octanoate, aqua(2,9‐dimethyl‐1,10‐phenanthroline)NiCl 2 complex, nickel oxalate,, dinuclear nickel(II) Schiff base complex and nickel acetate are reported. However, preparing the NiONPs by thermal decomposition of organometallic complex needs either numerous steps or surfactants or other toxic chemicals.…”

NiO nanoparticles catalyzed three component coupling reaction of aldehyde, amine and terminal alkynes

“…Nickel oxide nanoparticles (NiO NPs) are used in sensors [1], catalysis [2,3], electrochromic windows [4], glycerol stream reforming [5], photocatalyst [6], energy storage [7] etc. Various research groups have paid their attention towards the synthesis of NiO NPs using several methods such as solvothermal [8], sol-gel technique [9], colloidal precipitation [10], thermal decomposition method [11], and microwave [12] etc.…”