The superior photocatalytic performance and DFT insights of S-scheme CuO@TiO2 heterojunction composites for simultaneous degradation of organics

Abstract

The necessity to resolve the issue of rapid charge carrier recombination for boosting photocatalytic performance is a vigorous and challenging research field. To address this, the construction of a binary system of step-scheme (S-scheme) CuO@TiO2 heterostructure composite has been demonstrated through a facile solid-state route. The remarkably enhanced photocatalytic performance of CuO@TiO2, compared with single TiO2, which can consequence in the more efficient separation of photoinduced charge carriers, reduced the band gap of TiO2, improved the electrical transport performance, and improved the lifetimes, thus donating it with the much more powerful oxidation and reduction capability. A photocatalytic mechanism was proposed to explain the boosted photocatalytic performance of CuO@TiO2 on a complete analysis of physicochemical, DFT calculations, and electrochemical properties. In addition, this work focused on the investigation of the stability and recyclability of CuO@TiO2 in terms of efficiency and its physical origin using XRD, BET, and XPS. It is found that the removal efficiency diminishes 4.5% upon five recycling runs. The current study not only promoted our knowledge of the binary system of S-scheme CuO@TiO2 heterojunction composite photocatalyst but also shed new light on the design of heterostructure photocatalysts with high-performance and high stability.

The superior performance of silica gel supported nano zero-valent iron for simultaneous removal of Cr (VI)

“…A stock solution of Cr(VI)) with a concentration of 1000 mg L -1 was prepared by dissolving 0.2829 g of K 2 Cr 2 O 7 in distilled water (1000 mL) and another stock solution of acid blue-25 dye was prepared. The pH values were adjusted using 0.1 M of NaOH or HCl and the effect of pH (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11) was investigated as well as the effect of initial Cr(VI) concentration (5-100 mg L −1 ) on the removal efficiency was studied at an adsorbent dose of 0.1 g, solution volume of 100 mL, contact time of 120 min, temperature of 20 °C and agitation rate of 200 rpm. The effects of the existence of cations such as Mg 2+ , Zn 2+ and Cu 2+ , anions viz., NO www.nature.com/scientificreports/ PO 4 3and humic acid on the removal efficacy were investigated.…”

“…Various techniques such as photocatalysis, chemical precipitation, membrane filtration, coagulation and biological processes have been employed for the removal of Cr(VI) and dyes [11][12][13][14][15][16] . However, the aforementioned techniques have some defects such as the low removal performance, high cost and generation of secondary contaminants [17][18][19] .…”

Sputtering-Assisted Synthesis of Copper Oxide–Titanium Oxide Nanorods and Their Photoactive Performances

“…The modification of TiO 2 nanorods with copper oxides described herein might have changed the electronic state of Ti in Ti-O because of the formation of heterojunctions between the n-type TiO 2 and p-type copper oxides. This has been demonstrated with CuO@TiO 2 powders and core–shell N-TiO 2 @CuOx heterojunction composites formed using ball milling [ 38 , 39 ]. Notably, the Cu/Ti atomic ratio of TC350 was evaluated to be 3.6.…”

Preparation, Characterization and Photocatalytic Activity studies of Ag+, Cu2+ and Sn2+-doped Li2GeTeO6 under Visible Light Irradiation

“…S4b; supporting information), two notable characteristic peaks at 933.4 and 953.5 eV can be endorsed to Cu 2p3/2 and Cu 2p1/2, respectively. Two satellite peaks at 942.5 and 962.5 eV are also visible, indicating the presence of Cu 2+ in the Cu-LGTO sample [32]. The characteristic peaks at 486.6 and 495.2 eV (Fig.…”