Electrocatalytic and Enhanced Photocatalytic Applications of Sodium Niobate Nanoparticles Developed by Citrate Precursor Route

Abstract

Development of cost effective and efficient electrocatalysts is crucial to generate H2 as an alternative source of energy. However, expensive noble metal based electrocatalysts show best electrocatalytic performances which acts as main bottle-neck for commercial application. Therefore, non-precious electrocatalysts have become important for hydrogen and oxygen evolution reactions. Herein, we report the synthesis of high surface area (35 m2/g) sodium niobate nanoparticles by citrate precursor method. These nanoparticles were characterized by different techniques like X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. Electrocatalytic properties of cost-effective sodium niobate nanoparticles were investigated for HER and OER in 0.5 M KOH electrolyte using Ag/AgCl as reference electrode. The sodium niobate electrode showed significant current density for both OER (≈2.7 mA/cm2) and HER (≈0.7 mA/cm2) with onset potential of 0.9 V for OER and 0.6 V for HER. As-prepared sodium niobate nanoparticles show enhanced photocatalytic property (86% removal) towards the degradation of rose Bengal dye. Dielectric behaviour at different sintering temperatures was explained by Koop’s theory and Maxwell-Wagner mechanism. The dielectric constants of 41 and 38.5 and the dielectric losses of 0.04 and 0.025 were observed for the samples sintered at 500 °C and 700 °C, respectively at 500 kHz. Conductivity of the samples was understood by using power law fit.

Carbon dioxide photoreduction in prebiotic environments

“…As a photocatalyst active for the CO 2 conversion, CdS can also do its work when used as an electrocatalyst [57,63,68]. We report therein the literature's results obtained by the use of some potentially prebiotic metal sulfides as electrocatalyst for the CO 2 reduction, as they can be potentially active as photocatalysts [69,70], although careful experimental conditions tuning must be performed and discordant results can be obtained when shifting from electrocatalysis to photocatalysis and vice versa [71]. A study by Kitadai et al using various single-metal sulfides (Ag 2 S, CdS, CoS, CuS, FeS, MnS, MoS 2 , NiS, PbS, WS 2 , and ZnS) demonstrated that CdS and Ag 2 S function as excellent CO production catalysts [72].…”

Efficient Multifunctional Catalytic and Sensing Properties of Synthesized Ruthenium Oxide Nanoparticles

“…The slurry was prepared by sonicating 2.5 mg of catalysts in 0.5 mL of isopropanol with 0.1 mL of Nafion solution for 10 min. Then a drop of the slurry was cast on the surface of glassy carbon and dried at 60 • C in vacuum oven [46,47]. The loaded amount of the nanoparticles was of~0.30 mg/cm 2 on the GC electrode, and the area of the working electrode was 0.07 cm 2 .…”

Silver-doped SnO2nanostructures for photocatalytic water splitting and catalytic nitrophenol reduction

“…Hence, to achieve good quantum efficiency in photocatalysis, the electron–hole pair separation efficiency and the ability of light utilization of the photocatalysts should be enhanced. 30–32 Thus, to increase the charge separation and spread the energy range of photoexcitation, the doping of foreign elements in semiconductor oxides is considered to be a suitable strategy. As a result of the doping, defects can be created in semiconducting oxides, such as trapped states and oxygen vacancies, which effectively inhibit the recombination of electron–hole pairs owing to the capturing of electrons alone, thus improving the performances of metal oxides in photocatalysis.…”