Layered Nanocomposite 2D-TiO2 with Cu2O Nanoparticles as an Efficient Photocatalyst for 4-Chlorophenol Degradation and Hydrogen Evolution

Abstract

New composites formed by layered hybrid TiO 2 (stearic acid) (LHTiO 2 ) and, Cu 2 O nanoparticles were studied as photocatalysts that extend the response range to light visible for the evolution of hydrogen and the degradation of 4-chlorophenol. The results revealed that LHTiO 2 /Cu 2 O exhibited a clearly improved photocatalytic degradation, about 5.6 times faster than pristine TiO 2 , and hydrogen evolution of about 2.7 times higher than the TiO 2 anatase. The enhanced photocatalytic activity can be assigned to the properties of the two-dimensional morphology, in sheets-like arrangement of LHTiO 2 , benefitting from the high exposure of surface, with more active sites available to improve matching with the surfaces of the Cu 2 O nanocrystals and significant reduction of migration distances of photogenerated carriers. In the photocatalytic degradation, a mechanism Z-scheme is supported, and in the photocatalytic evolution of hydrogen a mechanism type II band alignment is indicated. Photocatalytic reuse tests showed that stability and catalytic activity of LHTiO 2 /Cu 2 O were maintained for three cycles. Photoelectrochemical evaluation were performed through measurements of the photocurrent response and electrochemical impedance.

Two-Dimensional Titanium Dioxide–Surfactant Photoactive Supramolecular Networks: Synthesis, Properties, and Applications for the Conversion of Light Energy

“…Complete photodegradation of 4-CP catalyzed by TiPA-A/V 2 O 5 was achieved after 120 min with a rate constant of 0.016 min −1 , approximately 2 times faster than TiPA-A and 12 times faster than anatase, as suggested by the graph ln (C/C 0 )/irradiation time, a regular degradation pseudo-first-order process that fits the Langmuir–Hinshelwood model ( Figure 5 d). The improved photocatalytic behavior of TiPA and TiPA-NPs heterosupramolecular materials with respect to anatase agrees with previous reports on other TiO 2 -based systems using other fatty acids and different pollutants targets [ 16 , 55 ] and reinforces the suggested trend of the concept that soft hybrid semiconductors could be an alternative to conventional purely inorganic photocatalysts. Due to their large bandgap, the best photocatalytic performance of the TiO 2 –PA-NPs samples could be attributed to the decrease in the recombination of the photogenerated electrons and holes and a closer interface between the heterosupramolecular materials with the surfaces of the nanoparticles.…”

“…Experiments were performed following the usual protocols in the current literature [ 16 , 55 ]. The photocatalytic response of both Ti-PA nanocomposites and their sensitized compounds was systematically compared with that of TiO 2 anatase nanoparticles commonly used as reference photocatalysts.…”

“…In our cases, the parameters a and d TiO2 , the width of the inorganic layer, are determined by the crystal structure of the TiO 2 sheet, so the free interlayer space, d free , can be directly calculated from the experimental XRD (00l) repeat distance ( d XRD ). Parameter t , introducing the minimal energy condition (VdW diameter of the chains), as discussed above, is typical of the system under given work conditions, and it is possible to estimate either experimentally from Bragg lateral reflections or from the literature [ 30 , 55 , 61 ]. For a family of products, the intensity of lateral reflections at ~20° in 2θ is generally very low and often impossible to detect, but their position is always the same independent of the surfactant.…”

Self-Assembled Sandwich-like MXene-Derived Composites as Highly Efficient and Sustainable Catalysts for Wastewater Treatment

“…29 Therefore, many researchers have coupled TiO 2 with other metals or semiconductors to separate photogenerated electron hole pairs (including electron capture, energy band gap matching, and the plasmon effect), thereby extending the life of photogenerated carriers. 30 The band gap of cuprous oxide (Cu 2 O) is 2.0−2.2 eV, which has a visible-light response. It is not only widely used in solar energy conversion and organic catalysis but also has good application prospects in water catalytic reactions and gas catalytic reactions.…”

Cuboidal Cu 2 O nanoparticles dispersed granular Mn 0. 05 Cd 0 . 95 S form a p‐n heterojunction for efficient photocatalytic hydrogen evolution

“…Figure 3B shows the XPS peak of Cu 2p. Compared with pure Cu 2 O, in MC‐5, there are two obvious peaks of Cu + that located near at 932.04 and 951.90 eV are Cu 2p 3/2 and Cu 2p 1/2 peaks, 37 which may be caused by the presence of Cu + characteristic peak of Cu 2 O in MC‐5. There are two oscillating peaks at 953.93 and 934.03 eV with high binding energy, which are related to the chemical state of Cu 2+ , 38 the results show that weak oxidation phenomenon occurred on the surface of Cu 2 O.…”