Exceptional visible-light photoelectrocatalytic activity of dual Z-scheme Bi@BiOI-Bi2O3/C3N4 heterojunction for simultaneous remediation of Cr(VI) and phenol

Shining light on broad-spectrum responded NaYF4:Yb,Er,Tm@Bi@BiOI: Understanding the enhanced photodegradation performance of bisphenol A and mechanisms

This work reported a novel ternary heterogeneous photocatalyst NaYF4:Yb,Er,Tm@Bi@BiOI (NBEG-6h). NBEG-6h exhibits broad-spectrum absorption from ultraviolet to near-infrared. The elimination efficiency of BPA by NBEG-6h under simulated sunlight and near-infrared light irradiation was 88% (24 min) and 93.9% (160 min), respectively. It also has the universality of degrading various pollutants, good reusability and stability. The exceptional photocatalytic activity can be attributed to the absorption of near-infrared light by NaYF4:Yb,Er,Tm, which improves the total efficiency of sunlight utilization. The localized surface plasmon resonance effect of Bi nanoparticles enhances the light absorption performance of the heterostructure. Furthermore, combining Bi and BiOI accelerates carrier migration and improves the separation efficiency of photogenerated electron-hole pairs. h+, ·O2- and 1O2 play the pivotal roles during the photocatalytic process. This research offers new insights into the design, development, and mechanism understanding of full-spectrum-driven heterostructure photocatalysts. It provides an environmentally sustainable approach to the treatment of harmful organic pollutants.

Controllable fabrication of SbxBi2-xS3 solid solution photocatalysts with superior elimination for Cr(VI)

The development of environmentally friendly and cost-effective photocatalysts is of vital significance for the effective removal of heavy metal contamination in water, but it is still a crucial challenge. Herein, the novel SbxBi2-xS3 solid solution photocatalysts with a certain amount of sulfur vacancy were prepared by adjusting the molar ratio of Sb to Bi through a simple hydrothermal strategy, and was applied to the effective photocatalytic reduction of hexavalent chromium (Cr(VI)). Sb1.75Bi0.25S3 with optimized ratio has superior reduction performance of Cr(VI), and the photocatalytic efficiency of Cr(VI) can achieve 91.9 % within 1 h of visible light illumination. The remarkable catalytic efficiency is due to the more applicable band structure of the solid solution photocatalyst, which is conducive for the photocatalytic reaction. Moreover, the substitution of Bi causes the crystal distortion of Sb2S3 and induce the generation of sulfur defects, which can effectively capture photoelectrons, accelerate the carriers separation, and improve the reduction performance. This study provides a hopeful photocatalyst for wastewater purification and promotes the exploration of solid solution photocatalyst in water environment remediation.

Highly reusable Bi2O3/electron-Cu-shuttle in-situ immobilized polyacrylonitrile fibrous mat for efficient photocatalytic degradation of methylene blue and rhodamine B dyes

Organic semiconductor-based photocatalysts have been alluring due to their edge over inorganic photocatalysts. In this study, a reusable copper-bismuth oxide/polyacrylonitrile (Cu-Bi2O3/PAN) fibrous mat was prepared by fast-process flame spray pyrolysis and electrospinning for photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB) dyes. The results confirmed a well-defined morphology of Cu-Bi2O3/PAN fibers and good coordination of flame-made Cu-Bi2O3 particles with the functional groups of PAN. The Cu-Bi2O3/PAN fibrous mat exhibits remarkable photocatalytic performance of 96.2% MB and 98.6% RhB degradation, with a reaction rate as high as about 4.5- and 10.2-times than that of flame-made Cu-Bi2O3 particles and PAN under neutral condition, even after 10 cycles. The Cu-Bi2O3/PAN exhibits complete degradation of MB and RhB in 90 and 150 min under alkaline and slightly acidic conditions, respectively. The synergistic effect of Cu-Bi2O3 and coordination bond between particles and functional groups of PAN promoted carrier migration, suppressed recombination of carriers and provided abundant radicals on the surface of the mat. Superoxide and hydroxyl radicals were the major active species involved in the degradation of RhB and MB, respectively. This work provides an insight into designing the Cu-metal-shuttle based photocatalysts to optimize fibrous mat application in water remediation.

Enhanced carbon dioxide adsorption and carrier separation over amine functionalized zirconium metal organic framework/gold/indium oxide for boosting photocatalytic carbon dioxide reduction

Photocatalytic CO2 conversion is a prospective way to mitigate greenhouse effect. In2O3 is widely used in the resource conversion of CO2, but still exists a few drawbacks containing limited CO2 capture and activation, narrow light absorption range, low charge separation and utilization. To overcome these disadvantages, an NH2-UiO-66/Au/In2O3 composite photocatalyst is built, with Au nanoparticles and NH2-UiO-66 decorated on the surface of In2O3 nanorods. Significantly, the improved carrier separation ability is attributed to the Schottky junction at the Au/In2O3 interface and the heterostructure between In2O3 and NH2-UiO-66. And the widened light absorption is attributed to the plasmon effect caused by Au nanoparticles. Moreover, the increase of CO2 adsorption and activation is mainly due to the porosity of NH2-UiO-66, thereby greatly improving photocatalytic CO2RR efficiency of NH2-UiO-66/Au/In2O3 nanorods. The CO yield of NH2-UiO-66/Au/In2O3 is 8.56 μmol g-1 h-1, which is nearly 45 times that of In2O3. This work will present a novel idea to design high-efficient composite photocatalysts for CO2 reduction by multifunctional component synergistic enhancement.

Bi/BiOI/carbon quantum dots nano-sheets with superior photocatalysis

A new photocatalyst of Bi/BiOI/Carbon quantum dots (CQDs) was synthesized via a simple method. Photocatalytic performance of Bi/BiOI/CQDs was evaluated by photodegradation of RhB. Experiment indicated that the introduction of CQDs could improve the photocatalysis activity of BiOI obviously. Moreover, there is a optimum percentage of CQDs. In this photocatalytic system, the enhanced photoactivity was mainly attributed to the heterojunction interface between CQDs and BiOI, as well as the enhanced light harvesting for the appropriate CQDs introduction. The radicals trapping experiments revealed that O2˙-, ˙OH and h+ were the main active species during the photocatalysis process.

Type-I heterojunction destruction by In situ formation of Bi2S3 for split-type photoelectrochemical aptasensor

Development of new strategies in photoelectrochemical (PEC) sensors is an important way to realize sensitive detection of biomolecule. In this study, mesoporous silica nanospheres (MSNs)-assisted split-type PEC aptasensor with in situ generation of Bi₂S₃ was proposed to achieve reliable detection of prostate-specific antigen (PSA). To be more specific, this bioresponsive release system will release large amounts of Na₂S by the reaction between PSA and aptamer that capped Na₂S-loading MSNs. Next, the Na₂S reacts with Bi to yield BiOI/BiOBr/Bi₂S₃ composite, which leads to an alteration in the electron-hole transfer pathway of the photoelectric material and a decrease in the response. As the PSA concentration increases, more Na₂S can be released and lower photocurrent is obtained. The linear range under the optimal experimental conditions is 10 pg·mL^-1-1 μg⋅mL^-1, and the detection limit is 1.23 pg⋅mL^-1, which has satisfactory stability and anti-interference.