Polyaniline/reduced graphene oxide nanosheets on TiO2 nanotube arrays as a high-performance supercapacitor electrode: Understanding the origin of high rate capability

Enhanced Electrochemical Performance of Polyaniline-Boron Doped Diamond Electrode for Supercapacitor Applications

Understanding how to tune the properties of electroactive materials is a key parameter for their applications in energy storage systems. This work presents a comprehensive study in tailoring polyaniline (PANI) suspensions by acid-assisted polymerization method and their subsequent deposition on boron-doped diamond (BDD) supports with low/high B concentrations. The porous or densely packed morphology of PANI is successfully controlled by varying the monomer-to-initiator ratio. The interaction between PANI and BDDs leads to the shift in oxidation and reduction potentials, and the high B doping resulted in the reduction of the oxidation potentials. Notably, the highest specific capacitance of 958 F g-1, which represents 90% of the theoretical capacitance, is recorded for the support with relatively low B content. Moreover, PANI obtained by slow kinetic has a stronger interaction with the B-doped diamond support, which is confirmed by electrochemical impedance spectroscopy. This study provides valuable insights for optimizing PANI suspension preparation methods and selecting appropriate boron doping concentrations in nanodiamond supports for composite electrodes in energy storage applications.

Edge interface microenvironment regulation of CoOOH/commercial activated carbon nano-hybrids enabling PMS activation for degrading ciprofloxacin

Peroxymonosulfate (PMS) is widely employed to generate oxygen-containing reactive species for ciprofloxacin (CIP) degradation. Herein, cobalt oxyhydroxide @activated carbon (CoOOH@AC) was synthesized via a wet chemical sedimentation method to activate PMS for degradation of CIP. The result suggested AC can support the vertical growth of CoOOH nanosheets to expose high-activity Co-contained edges, possessing efficient PMS activation and degradation activity and catalytic stability. In the presence of 3.0 mg of optimal CoOOH@AC and 2 mM PMS, 96.8 % of CIP was degraded within 10 min, approximately 11.6 and 9.97 times greater than those of CoOOH/PMS and AC/PMS systems. Notably, it was disclosed that the optimal CoOOH@AC/PMS system still exhibited efficient catalytic performance in a wide pH range, different organics and common co-existing ions. Quenching experiments and electron paramagnetic resonance indicated that both radical and non-radical processes contributed to the degradation of CIP, with 1O2 and direct electron transfer accounting for the non-radical pathway and SO4•- and •OH serving as the main radical active species. Finally, possible CIP degradation pathways were proposed based on high-performance liquid chromatography-mass spectrometry. This study provided an alternate method for wastewater treatment based on PMS catalyzed by cobalt-based hydroxide.

Controllable synthesis of Na, K-based titanium oxide nanoribbons as functional electrodes for supercapacitors and separation of aqueous ions

By facile controllable preparation, as-synthesized NTO and KTO exhibit remarkable electrochemical behavior for the applications of supercapacitors and capacitive deionization.

Electrochemical Performance of Titania 3D Nanonetwork Electrodes Induced by Pulse Ionization at Varied Pulse Repetitions

Pulse ionized titania 3D-nanonetworks (T3DN) are emerging materials for fabricating binder-free and carbon-free electrodes for electrochemical energy storage devices. In this article, we investigate the effect of the one of the most important fabrication parameters, pulse frequency, for optimizing supercapacitor efficiency. A series of coin cell batteries with laser-induced electrodes was fabricated; the effect of pulse frequency on oxidation levels and material properties was studied using both experimental and theoretical analysis. Also, detailed electrochemical tests including cyclic voltammetry (CV), charge/discharge, and electrochemical impedance spectroscopy (EIS) were conducted to better understand the effect of pulse frequency on the electrochemical performance of the fabricated devices. The results show that at a frequency of 600 kHz, more T3DN were observed due to the higher temperature and stabler formation of the plasma plume, which resulted in better performance of the fabricated supercapacitors; specific capacitances of samples fabricated at 600 kHz and 1200 kHz were calculated to be 59.85 and 54.39 mF/g at 500 mV/s, respectively.