Preparation of cube micrometer potassium niobate (KNbO3) by hydrothermal method and sonocatalytic degradation of organic dye

Abstract

Cube micrometer potassium niobate (KNbO3) powder, as a high effective sonocatalyst, was prepared using hydrothermal method, and then, was characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). In order to evaluate the sonocatalytic activity of prepared KNbO3 powder, the sonocatalytic degradation of some organic dyes was studied. In addition, some influencing factors such as heat-treatment temperature and heat-treatment time on the sonocatalytic activity of prepared KNbO3 powder and catalyst added amount and ultrasonic irradiation time on the sonocatalytic degradation efficiency were examined by using UV-visible spectrophotometer and Total Organic Carbon (TOC) determination. The experimental results showed that the best sonocatalytic degradation ratio (69.23%) of organic dyes could be obtained when the conditions of 5.00 mg/L initial concentration, 1.00 g/L prepared KNbO3 powder (heat-treated at 400 °C for 60 min) added amount, 5.00 h ultrasonic irradiation (40 kHz frequency and 300 W output power), 100mL total volume and 25-28 °C temperature were adopted. Therefore, the micrometer KNbO3 powder could be considered as an effective sonocatalyst for treating non- or low-transparent organic wastewaters.

Periodate-assisted pulsed sonocatalysis of real textile wastewater in the presence of MgO nanoparticles: Response surface methodological optimization

“…In addition, excess amounts of suspended MgO nanoparticles inhibit ultrasonic waves to be passed into the bulk solution [17]. The aggregation and subsequently, shielding effect cause the decrease in the number of active sites placed on the surface of catalyst and interfere the transmission of ultrasonic waves in the bulk solution [30]. Interestingly, unlike our previous study [12], increasing sonocatalyst dosage up to 3 g/L led to no considerable decrease in the COD removal.…”

Copper(I) sulfide (Cu 2 S) nanoparticles from Cu(II) diethyldithiocarbamate: Synthesis, characterization and its application in ultrasound-assisted catalytic degradation of organic dye pollutants

“…Although, the exact mechanism for this sonocatalytic degradation reaction over Cu2S nanoparticles is not very clear and intermediates were not observed directly; on the basis of the above observations and previously reported mechanisms [45][46][47][48][49][50][51][52], the following mechanism was…”

Preparation of Er3+:Y3Al5O12/KNbO3 composite and application in innocent treatment of ketamine by using sonocatalytic decomposition method

“…8. The proposal of sonocatalytic degradation mechanism is mainly based on both sonoluminescence and "hot spot" resulting from the ultrasonic cavitation effect [24]. This may be one of the well known and acceptable mechanisms.…”

“…Sonocatalytic degradation of organic pollutants can be explained by the ultrasonic cavitation effect happened in aqueous medium, which leads to the sonoluminescence and "hot spot" [21][22][23][24][25]. During ultrasonic cavitation the produced "hot spot" can give transient high temperatures (5000 K) and high pressures (1000 atm) [26][27][28][29].…”