Electrosynthesis and photoelectrochemical properties of polyaniline/SiC nanohybrid electrodes

Template-free efficacious morphology of electrosynthesized polyaniline/β-cyclodextrin host-guest complex on Au/rGO modified electrode for removal and recovery of rare-earth and heavy elements from seawater

Global water pollution and scarcity of water resources are turning increasingly into serious threats to the survival of all living organisms on Earth. This study offers an influent strategy for the electrosynthesis of reduced graphene oxide/polyaniline/β-cyclodextrin (rGO/PAni/βCD) nanocomposite and its application to the removal/recovery of heavy elements (HEs) and rare-earth elements (REEs). Besides physicochemical and electrochemical studies, the surface morphological and statistical properties of fabricated nanocomposite electrode were examined. The textural and morphological characteristics of nanocomposite electrode were investigated via AFM data based on statistical, stereometric, and fractal theory. The cohesive, porous, and well-developed morphology of fabricated nanocomposite electrode has enabled the electrodeposition technique to achieve significant simultaneous removal/recovery efficiency of HE and REE ions such as Pb(II), Cu(II), Cd(II), Hg(II), Ce(IV), and Nb(V). Therefore, using rGO/PAni/βCD, considerable removal of HEs and REEs was achieved under optimized pH, 0.1 M KNO3, and 35 mg L-1 metal ion initial concentration during 20 min. Removal capacity of the nanocomposite electrode is preserved subsequent to 10 cycles of electrodeposition/desorption, according to the desorption investigation through eluted adsorbent at time intervals in deionized water and adjusted acidic pH values. Then, using rGO/PAni/CD nanocomposite, simulated seawater remediation was accomplished successfully. This interdisciplinary approach reveals that the removal/recovery efficiency enhance linearly along with the improvement of well-developed morphology for electrosynthesized composites. Thus, these results suggest how the morphological features of the polymer composites could improve remediation of water resources.

One-step solvothermal fabrication of Cu@PANI core-shell nanospheres for hydrogen evolution

Polyaniline(PANI)-decorated Cu nanoparticles were prepared by a facile solvothermal method. Different reaction temperatures resulted in different morphologies of the Cu/PANI composites, which exhibited good photocatalytic activities. When the mass ratio of PANI increased to 2.5 wt%, the H2 evolution rate reached 1.97 mmol g-1 h-1 in lactic acid solution under solar light irradiation, which is about 2 times higher than that of pure Cu nanoparticles (1.06 mmol g-1 h-1). The introduction of PANI can improve the separation efficiency of the photo-generated electron-hole pairs, where PANI acts as a hole reservoir for trapping holes generated by the Cu NPs and hindering the recombination of the electron-hole pairs. A possible mechanism is presented to explain the photocatalytic process using Cu@PANI core-shell nanospheres as the photocatalyst.