Highly Efficient Photothermal Reduction of CO2 on Pd2Cu Dispersed TiO2 Photocatalyst and Operando DRIFT Spectroscopic Analysis of Reactive Intermediates.

The photocatalytic conversion of CO2 to fuels using solar energy presents meaningful potential in the mitigation of global warming, solar energy conversion, and fuel production. Photothermal catalysis is one promising approach to convert chemically inert CO2 into value-added chemicals. Herein, we report the selective hydrogenation of CO2 to ethanol by Pd2Cu alloy dispersed TiO2 (P25) photocatalyst. Under UV-Vis irradiation, the Pd2Cu/P25 showed an efficient CO2 reduction photothermally at 150 °C with an ethanol production rate of 4.1 mmol g-1 h-1. Operando diffuse reflectance infrared Fourier transform (DRIFT) absorption studies were used to trace the reactive intermediates involved in CO2 hydrogenation in detail. Overall, the Cu provides the active sites for CO2 adsorption and Pd involves the oxidation of H2 molecule generated from P25 and C-C bond formation.

Studies on the sonochemical polymorphism of Sb2O3 on activated graphite for the electrochemical determination of imipramine.

This work reports the simultaneous sonochemical activation of graphite and sonohydrolysis of antimony chloride (SbCl3) in the alkaline medium. The experiments conducted by bath sonicator operated at 37 kHz of frequency and a maximum power of 150 W. The simple sonohydrolysis of SbCl3 alone produced an orthorhombic phase of Sb2O3, whereas, it produced mixed phases of cubic and orthorhombic Sb2O3 when introduced with graphite. Herein, the activated graphite (aGR) provides the best support to the growth of cubic phase. This cubic Sb2O3 is grown only on the graphite basal planes, which confirmed by scanning electron microscope. Moreover, the phase changes have identified by the X-ray diffraction, Raman and X-ray photoelectron analysis. The prepared aGR-Sb2O3 composite has applied to the electroanalytical studies of anti-depressant drug imipramine (IMP). The results showed that aGR-Sb2O3 revealed better activity than Sb2O3; the reasons are discussed comprehensively. Furthermore, aGR-Sb2O3 exhibited comparable analytical results for the determination of IMP.

Effect of cavitation erosion in the sonochemical exfoliation of activated graphite for electrocatalysis of acebutolol.

This study mainly covered the cavitation erosion in probe sonication and its electrochemical behavior. The activated graphite was exfoliated by the probe sonication wherein the titanium alloy (TA) is used as a probe (micro-tip). The sonication performed in the aqueous solution contains a mixture of sulfuric acid and nitric acid (1:1). The exfoliated graphite (EG) was examined by field emission scanning electron microscope, Raman and X-ray diffraction pattern analysis. The results showed that some TA particles dissolute from the TA micro-tip accompanied with graphite exfoliation. This dissolution experienced from the cavitation erosion, because the acoustic cavitation makes severe deformation on probe tips due to the bubble collapse. The dissolution rate increased when increasing sonication time; the resultant TA particles are randomly distributed over the EG. These EGTAs applied to the electrochemical oxidation of acebutolol which revealed an appreciable electrochemical performance and also exhibited better analytical performances to the electrochemical determinations. The obtained analytical parameters viz., sensitivity (0.234 µA µM-1 cm-2), linear range (0.01-15.1 µM), and limit of detection (0.003 µM) are highly comparable with the previous reports. Moreover, it has an acceptable tolerance with the interfering substances.