Importance of ZnTiO₃ Phase in ZnTi-Mixed Metal Oxide Photocatalysts Derived from Layered Double Hydroxide

Abstract

In this study, ZnTi-mixed metal oxides (ZTM), such as ZnTiO3, were synthesized from ZnTi layered double hydroxides by varying the molar ratio of Zn/Ti, calcination temperatures, and synthesis methods (hydrothermal or reflux). The surface electronic characteristics of ZTM were investigated by the energy-resolved distribution of electron traps (ERDTs) using reversed double-beam photoacoustic spectroscopy. The ZTM samples obtained by conducting hydrothermal synthesis at 500 °C showed similar ERDT patterns independent of the molar ratio of Zn/Ti, although ZnTiO3 phase was not observed in the X-ray diffraction pattern, when the Zn/Ti ratio was high. When the ERDT patterns demonstrated a high electron accumulation level near the conduction band bottom in hydrothermal products at 500 °C, a higher photocatalytic phenol degradation efficiency was observed due to the formation of ZnTiO3 phase. This suggested that the product with the high Zn/Ti molar ratio (Zn/Ti = 6) constituted amorphous ZnTiO3.The enhanced photocatalytic performance of ZTM could be attributed to the heterojunction of electrons among ZnO, TiO2, and ZnTiO3, which enabled electron transfer in the composites, prevented charge recombination, and promoted a wider visible light adsorption by ZnTiO3 phase irrespective of its crystallinity.

Cubic Cu2O nanoparticles decorated on TiO2 nanofiber heterostructure as an excellent synergistic photocatalyst for H2 production and sulfamethoxazole degradation

“…A light beam from an Xe lamp with a grating monochromator modulated at 80 Hz by a light chopper was irradiated from 650 nm to 350 nm through the cell window to detect the PAS signal using a digital lock-in amplifier. The energy-resolved distribution of electron traps (ERDT) was obtained by determining the amount of photoabsorption change for the accumulated electrons [24,25].…”

MoOx-Decorated Co-Based Catalysts toward the Hydrodeoxygenation Reaction of Biomass-Derived Platform Molecules

“…, Cu-, Co-, and Ni-based) catalysts supported on metal oxide substrates according to the versatility in the chemical composition and especially structural transformation property. This strategy not only provides an adjustable morphology of metal nanoparticles with a high dispersion and stability but also offers an efficient route to precisely modulate the geometric/electronic structure of interfacial sites. − This excellent property of LDH precursors inspires us to study the preparation of transition metal catalysts with the activation ability toward CO/CO in LA so as to achieve a high GVL selectivity via the hydrodeoxygenation reaction of LA.…”

Synthesis of the ZnTiO3/TiO2 Nanocomposite Supported in Ecuadorian Clays for the Adsorption and Photocatalytic Removal of Methylene Blue Dye

“…During the synthesis, the transformation of the crystalline phases presents different products, which depend on the initial molar ratio of the reactants and the calcination temperatures. The presence of anatase and rutile can also affect the behavior of the phases [ 23 ].…”