Synthesis of Layered Double Hydroxides and TiO₂ Supported Metal Nanoparticles for Electrocatalysis

Abstract

In the present work, solution‐phase synthesis was employed to prepare two sets of catalysts with different transition metals as active sites. One set contained Au or Pd supported on TiO2 (Au−TiO2, Pd−TiO2), whereas the other set contained layered double hydroxides (NiFe‐LDH and CuFe‐LDH). The electrocatalytic performance of these composite materials was investigated by cyclic voltammetry (CV) using a model compound 4‐nitrophenol (4‐NP). Composite materials were characterized by various analytical techniques to gain insight into the catalysts active sites. The morphology and structure of the prepared samples were investigated by X‐ray diffraction, attenuated total reflectance Fourier transform infrared, X‐ray photoelectron spectroscopy, transmission scanning electron microscope, and field emission scanning electron microscope. Metal nanoparticles loading on TiO2 was measured by inductively coupled plasma – optical emission spectrometry. CV measurements were performed in acetonitrile solution containing 0.1 m tetrabutylammonium hexafluorophosphate (TBAPF6) and 1 mm 4‐NP. Among all dioxides (Au−TiO2, Pd−TiO2) and hydroxides (NiFe‐LDH and CuFe‐LDH) studied, Pd−TiO2 shows the lowest onset potential (−0.32 V vs. Ag/AgCl) for the electrocatalytic reduction of 4‐NP. This is the first comparative study of such materials for 4‐NP electrocatalysis in aprotic solvent, thus demonstrating the suitability of dioxide and hydroxide based materials as electrocatalysts.

Recent Advancement in Quantum Dot Modified Layered Double Hydroxide towards Photocatalytic, Electrocatalytic, and Photoelectrochemical Applications

“…The measurement of catalyst longevity comprises two preliminary methods: (i) recording chronopotentiometry (CP), which tracks variation of potential over time, or chronoamperometry (CA), which monitors the variation of current with time, under a persistent potential (I-t curve); and (ii) measuring LSV curves before and after CV recycling. [86,87] However, several works have been reported over carbonaceous QDs modified LDH for electrocatalytic water splitting. The mechanical strength, thermal stability, conductivity, and specific surface area are the unique physicochemical features of carbonaceous QDs making them a better catalyst for water electrolysis.…”

“…In practical applications, the extended resilience of catalysts over time is also a crucial parameter for assessing their quality. The measurement of catalyst longevity comprises two preliminary methods: (i) recording chronopotentiometry (CP), which tracks variation of potential over time, or chronoamperometry (CA), which monitors the variation of current with time, under a persistent potential (I–t curve); and (ii) measuring LSV curves before and after CV recycling [86,87] …”

Constructing Quantum Dots/Nano TiO2/ASC Composites as Tiny Electrodes with Efficient Electrocatalytic Property of Rhodamine B

“…TiO 2 is a cost-effective, safe, stable, and ecologically acceptable catalyst − that is extensively applied in photocatalysis for many chemical transformations, − such as the degradation of pollutants that have adverse environmental effects. Despite its various benefits, research on its role in electrocatalysis is lacking. − Additionally, TiO 2 is produced with high electrical resistance and limited surface area, which could limit the catalytic potential − when electrodes are coated with TiO 2 using traditional chemical procedures, such as hydrothermal treatment , and the polyol approach . Herein, TiO 2 is designed to be loaded on ASC using the sol–gel method to achieve electrochemical activity based on a previous study …”