Polyethylene glycol capped copper ferrite porous nanostructured materials for efficient photocatalytic degradation of bromophenol blue.

Three different types (blank, annealed, and functionalized) of copper ferrite nanoparticles (CuFe2O4) were synthesized by the co-precipitation method. The CuFe2O4 NPs were characterized by Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Energy-dispersive X-ray spectroscopy (EDX) techniques. FTIR analysis confirmed that 3-APTES is successfully grafted on the surface of CuFe2O4 NPs. XRD results show the amorphous nature of blank CuFe2O4 NPs, and crystalline structure was observed for annealed and functionalized CuFe2O4 NPs. XRD results revealed that crystallite size ranges from 23.6 to 34.6 nm. SEM micrographs of blank CuFe2O4 NPs show the irregular shape and size of the nanostructure. The spherical and strongly linked structure was seen in the micrograph of functionalized CuFe2O4 NPs. EDX analysis revealed the nanostructure composed of Fe, Cu, O, and a small percentage of Si. The photocatalytic degradation efficiency of synthesized CuFe2O4 NPs was examined under UV irradiation in an aqueous medium against bromophenol blue (BPB) dye. The effect of different parameters such as irradiation time and pH on the photodegradation of BPB dye was studied by all three types of CuFe2O4 photocatalyst. Results show that the maximum photocatalytic degradation efficiency was observed for functionalized CuFe2O4 nanoparticles that degraded 98% of BPB dye in the acidic medium at pH = 1. The optimum contact time for dye degradation was 120 min by synthesized photocatalyst. Photodegradation performance of blank and annealed CuFe2O4 NPs is less than 90%. The synthesized CuFe2O4 NPs were recycled and reused, which shows good photocatalytic degradation efficiency up to 4 consecutive cycles. The kinetic model displayed that degradation reaction followed pseudo 1st order kinetics. The blank, annealed, and functionalized CuFe2O4 NPs have turnover numbers of 10.7x10 (Mudhoo et al., 2019), 12.9x10 (Mudhoo et al., 2019), and 22.2x10 (Mudhoo et al., 2019) (kg-1 sec-1) accordingly. In conclusion, all results revealed the high efficiency of prepared photocatalyst for tested hazardous dye from wastewater and encouraged more work on photodegradation of organic pollutants from wastewater.

Exploring the electrochemical properties of CuSe-decorated NiSe2 nanocubes for battery-supercapacitor hybrid devices.

Chalcogenides, a promising class of electrode materials, attracted massive popularity owing to their exciting features of high conductive nature, high capacity, rich redox activities, and structural functionalities, making them the first choice for the electrochemical energy domain. This paper reported a new NiSe2-CuSe nanocomposite prepared via a wet-chemical synthesis followed by a low-cost and simple hydrothermal reaction. The physical characterization showed cubes and nanoparticles type morphological features of NiSe2 and CuSe products, while their composite reveals a combined morphological characteristic. The electrochemical properties were tested in an aqueous solution, demonstrating that the NiSe2-CuSe nanocomposite exhibits a high capacity of 376 C g-1, low resistance, good reversibility and rate capability in a three-electrode mode than bulk counterparts. For practical aspects, a battery-hybrid supercapacitor (BHSC) is developed with NiSe2-CuSe nanocomposite, and activated carbon (AC) serves as cathode and anode in two-cell mode operation. The built NiSe2-CuSe||AC/KOH BHSC expanded the voltage to 1.8 V and delivered the highest capacitance of 148 F g-1 and 55 F g-1 from 1 to 10 A g-1, suppressing most of the previously existing literature reports. Also, our built NiSe2-CuSe||AC/KOH BHSC displayed a high-power delivery of 8928 W kg-1 at a maximum energy density of 66.6 W h kg-1 and retained 91.7% capacitance after a long way of 10,000 cycles. These outstanding results demonstrate that metal selenides can be effectively utilized as alternative electrodes with high energy, rate performance, and long-term durability for advanced energy conversion and storage devices.