Designing advanced S‐scheme CdS QDs/La‐Bi₂WO₆ photocatalysts for efficient degradation of RhB

Abstract

Finding effective strategies to design efficient photocatalysts and decompose refractory organic compounds in wastewater is a challenging problem. Herein, by coupling element doping and constructing heterostructures, S‐scheme CdS QDs/La‐Bi2WO6 (CS/LBWO) photocatalysts are designed and synthesized by a simple hydrothermal method. As a result, the RhB degradation efficiency of the optimized 5% CS/LBWO reached 99% within 70 min of illumination with excellent stability and recyclability. CS/LBWO shows improvement in the adsorption range of visible light and promotes electron–hole pair generation/migration/separation, attributing the superior degradation performance. The degradation RhB mechanism is proposed by a free radical capture experiment, electron paramagnetic resonance, and high‐performance liquid chromatography‐mass spectrometry results, indicating that h+ and •O2– play a significant role during four degradation processes: de‐ethylation, chromophore cleavage, ring opening, and mineralization. Based on in situ irradiated X‐ray photoelectron spectroscopy, Mulliken electronegativity theory, and the work function results, the S‐scheme heterojunction of CS/LBWO promotes the transfer of photogenerated electron–hole pairs and promotes the generation of reactive radicals. This work not only reports that 5% CS/LBWO is a promising photocatalyst for degradation experiments but also provides an approach to design advanced photocatalysts by coupling element doping and constructing heterostructures.

Boosting Carrier Separation on a BiOBr/Bi4O5Br2 Direct Z-Scheme Heterojunction for Superior Photocatalytic Nitrogen Fixation

“…As discerned from the electrochemical impedance spectroscopy (EIS) spectra plots (Figure h), BiOBr/Bi 4 O 5 Br 2 shows the smallest semicircle size among the three photocatalysts, which can be credited to the lowest resistance for its interfacial electron transfer . In addition, BiOBr/Bi 4 O 5 Br 2 exhibits lower carrier recombination, as demonstrated by the photoluminescence (PL) spectra (Figure i) . Hence, in the direct Z-scheme BiOBr/Bi 4 O 5 Br 2 heterojunction, the internal electric field formed in the interface is capable of promoting the photoinduced electrons of Bi 4 O 5 Br 2 to recombine with the holes in BiOBr, achieving effective carrier separation and electron accumulation in the CB position of BiOBr, consequently facilitating the reduction of N 2 to NH 3 .…”

“…46 In addition, BiOBr/Bi 4 O 5 Br 2 exhibits lower carrier recombination, as demonstrated by the photoluminescence (PL) spectra (Figure 2i). 47 Hence, in the direct Z-scheme BiOBr/Bi 4 O 5 Br 2 heterojunction, the internal electric field formed in the interface is capable of promoting the photoinduced electrons of Bi 4 O 5 Br 2 to recombine with the holes in BiOBr, achieving effective carrier separation and electron accumulation in the CB position of BiOBr, consequently facilitating the reduction of N 2 to NH 3 .…”

Unusual aliovalent Cd doped γ‐Bi2MoO6 nanomaterial for efficient photocatalytic degradation of sulfamethoxazole and rhodamine B under visible light irradiation

“…The double exponential decay model fits the fluorescence attenuation data (Formula 1). [ 64 ] After fitting data, four optical parameters of life and coefficient can be obtained. Among them, the short‐lifetime $${{\boldsymbol{\tau }}}_{{\bf{1}}}$$ and long‐lifetime $${{\boldsymbol{\tau }}}_{{\bf{2}}}$$ represent the radiative process of carrier recombination and the nonradiative energy transfer process, respectively.…”

A Comprehensive Review on the Boosted Effects of Anion Vacancy in the Photocatalytic Solar Water Splitting: Focus on Sulfur Vacancy

“…Due to the impossible development of a highly efficient individual photocatalytic material because of the rapid photoinduced e/h recombination, various strategies, including coupled semiconductor systems, − doped semiconductors, ,− modified semiconductors’ surfaces, ,− engineered facet and interface, , cocatalyst loading and engineering of defects, − etc., have been applied to increase the photocatalytic activity of H 2 -evolution of the heterogeneous water splitting processes, or any photocatalytic reaction, in general. To design combinations of both photocatalysts and cocatalysts via semiconductor TMDCs, tuning with the layers’ thickness and heterojunction interface formation is a suitable strategy .…”