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Due to energy crises and environmental pollution worldwide, researchers have sought efficient electrocatalysts for oxygen evolution reaction (OER) and photocatalysts to eliminate organic pollutants. In the present work, we have synthesized a fullerene-C 60 -based CeO 2 @C 60 core-shell hybrid and characterized it with various state-of-art techniques to explore its OER performance and photocatalytic properties under natural sunlight. TEM nano-graphs and EDX color mapping exhibited the uniform covering of C 60 over CeO 2 forming a core-shell structure with a particle size of 54 nm. The XPS results demonstrate the coexistence of Ce3+ and Ce4+ oxidation states, resulting in the formation of rich oxygen vacancy defects, which induced the efficient charge transformation from CeO 2 to C 60 , enhancing the photocatalytic activity and promoting the OER reaction. The electrochemical measurements revealed a lower overpotential (312 mV) and small Tafel slope (54 mV/dec) at 10 mA/cm2 current density of CeO 2 @C 60 core-shell hybrid than pure CeO 2. Further, the hybrid is stable up to 2000th cycles, and the chronoamperometry test showed that it remains stable for 45 hr without degrading in 1 M KOH solution. The photocatalytic activity under natural sunlight irradiations showed that the CeO 2 @C 60 core-shell hybrid completely degraded P-nitroaniline (P-Nitro) organic pollutant after 75 min, with outstanding recyclability up to the 7th cycle of use. Furthermore, the present work explores the tremendous potential of C 60 and rare earth metal oxide-based hybrid catalysts having exceptional stability toward photocatalysis and electrochemical water splitting. [Display omitted] [ABSTRACT FROM AUTHOR]

Metal oxide nanoparticles and their composites with conducting polymers, specifically Polyaniline (PANI) were utilized for fabricating nanoscale supercapacitor (SC) electrode materials. In the present study, we have synthesized pristine Pr 2 O 3 , NiO, Co 3 O 4 nanoparticles, binary PANI-Pr 2 O 3 , PANI-NiO, PANI-Co 3 O 4 , ternary Pr 2 O 3 –NiO–Co 3 O 4 , and quaternary PANI-Pr 2 O 3 –NiO–Co 3 O 4 spherical core-shell nanocomposite using co-precipitation and ultra-sonication methods. The grown samples were characterized with different analytical techniques. The XRD pattern revealed that the as-synthesized products were crystalline with Pr 2 O 3 hexagonal phase, NiO cubic phase, and Co 3 O 4 cubic phase in pure and nanocomposites. The Williamson-Hall, Scherrer, and size-strain plot methods were employed to study the crystalline development and contribution of micro-strain. FTIR pattern exhibited the metal-oxygen and PANI bond vibrations. FE-SEM images shown the spherical core-shell shape morphology of quaternary nanocomposite. EDX evident the presence of praseodymium, cobalt, and nickel in synthesized samples. UV–vis spectroscopy confirmed the absorption in the visible region. The IV graphs showed a higher conductivity of quaternary nanocomposite. The cyclic voltammetry results revealed that the quaternary nanocomposite has a higher specific capacitance 500 Fg-1 as compared to binary nanocomposites 134 F g−1 (PANI-Pr 2 O 3), 143 F g−1 (PANI-Co 3 O 4), 256 F g−1 (PANI-NiO), and PANI (90.8 F g−1) at a scan rate of 5 m Vs−1. The GCD results also showed that the quaternary nanocomposite has a higher specific capacitance of 905 F g−1 at current density 1 A g−1 with maximum energy density and power density of 87.99 kWhkg-1 and 2.6 k W kg−1 , respectively. The EIS curve also confirmed that the quaternary nanocomposite has a lower polarization resistance (R p) and solution resistance (R s). The higher capacitance of quaternary nanocomposite can facilitate ion transfer, and the formation of its core-shell structure flourish to enhance surface-dependent electrochemical properties. Furthermore, this study gives a novel research idea to manufacture electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]

• Direct dual Z-scheme TiO-WO 3 -CeO 2 heterostructured nanocomposite successfully synthesized by co-precipitation route. • The nanocomposite TiO-WO 3 -CeO 2 showed boosted photocatalytic activity towards different pollutants. • Systematic investigations confirmed the superior charge separation by direct dual Z-scheme. • Enhanced antibacterial activity of nanocomposite against various pathogenic bacterial strain. • The higher super-capacitive behaviour of nanocomposite. [Display omitted] Direct dual Z-scheme heterostructured nanocomposite TiO 2 -WO 3 -CeO 2 (NC) and pristine metal oxides nanostructures (NSs) were fabricated using a facile co-precipitation route. XRD, FTIR, and Raman data have confirmed the formation of NSs and NC. FESEM images showed quasi-mesoporous morphology of as-grown nanocomposite. EDX analysis confirmed the existence of titanium (Ti), cerium (Ce), and tungsten (W) in grown NC. The energy bandgap of NC was narrow 2.45 eV as compared to NSs. The higher electrical conductivity and lower recombination rate of NC were observed in IV and PL analysis. The photodegradation efficiency of NC was recorded 99.8% after 60 min under sunlight radiation against methylene blue (MB), which was significantly higher than NSs. NC catalyst has shown excellent photodegradation against other organic pollutants and has superior recyclability up to 7th cycle toward MB dye with a ~ 6% deficit in photodegradation efficiency. The antimicrobial activity results indicated the higher inhibition ability of NC against E. coli , K. pneumoniae , S. aureus , P. Vulgaris , and P. aeruginosa with maximum inhibition zone diameter 25, 29, 26, 28, and 27 mm, respectively. The electrochemical tests including CV, EIS, and GCD exhibited the superior capacitive behaviour of NC. These results demonstrate that grown NC is an efficient material for electrochemical devices, water purification, and biomedical applications. [ABSTRACT FROM AUTHOR]