Photocatalytic Degradation Of RhB Research Articles

Rational design of CdS-enwrapped polypyrrole nanoparticles for wastewater treatment: removal of hazardous pollutants in aqueous solutions.

The modern world requires a chemical industry that can run at low production costs while producing high-quality products with minimal environmental impact. The development of environmentally friendly, cost-effective, and efficient wastewater treatment materials remains a majorproblem for the sustainable approach. We prepared nanoscale cadmium sulfide (CdS)-enwrapped polypyrrole (PPy) polymer composites for degradation of organic pollutants. The prepared CdS@PPy nanocomposites were characterized by powder X-ray diffraction, scanning electron microscope (SEM), field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible(UV) absorption spectroscopy, indicating proper intercalation between CdS and PPy. Consequently, the catalytic efficiency of the synthesized hybrid nanocomposites was analyzed through the degradation of methylene blue (MB) and rhodamine B (Rh B) under visible light irradiation. The measured degradation efficiency of the dye solutions under the photolysis process is about 18% and 23% for MB and Rh B dye, respectively. Furthermore, the recycle test result concludes that the CdS@PPy composite exhibits 91% and 89% of MB and Rh B dye degradation efficiency even at the 4th cycle, respectively. The positive synergistic impact of CdS and PPymay be the result of effective photocatalytic degradation of MB and RhB.

Fabrication and characterization of new Fe3O4@SiO2@TiO2-CPTS-HBAP (FST-CH) nanoparticles for photocatalytic degradation and adsorption removal of rhodamine B dye in the aquatic environment

In this study, Fe3O4@SiO2@TiO2-CPTS-HBAP (FST-CH) nanoparticle was prepared for the simultaneous adsorption and photocatalytic degradation of aromatic chemical pollutants (Rhodamine B dye) in aqueous solution. FST-CH nanoparticle was characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Energy Dispersive X-Ray (EDX) Fluorescence Spectrometer and X-Ray Diffraction (XRD) spectroscopy. The photocatalytic activity of rhodamine B dye (RhB) was evaluated with a Kerman UV 8/18 vertical roller photoreactor. About 56% of RhB in aqueous medium was adsorbed by FST-CH nanoparticles with only 45 min of stirring in the dark, and about 77.01% was degraded or converted to other structures under the photoreactor for 120 min. The photocatalytic degradation of RhB (apparent rate constant: 0.0026 mg dm-3 min-1) occurred by a pseudo-second order reaction. In addition, the recovery of the prepared magnetic FST-CH nanoparticle by an external magnetic field, exhibiting good magnetic response and reusability, shows that the obtained magnetic FST-CH nanoparticle is stable and maintains high degradation ratio and catalyst recovery even after four cycles. Thus, the prepared FST-CH nanoparticle can be highly recommended for its use in potential applications of water decontamination.

Charge-Selective Photocatalytic Degradation of Organic Dyes Driven by Naturally Occurring Halloysite Nanotubes

This study explores the use of Halloysite NanoTubes (HNTs) as photocatalysts capable of decomposing organic dyes under exposure to visible or ultraviolet light. Through a systematic series of photocatalytic experiments, we unveil that the photodegradation of Rhodamine B, used as a model cationic dye, is significantly accelerated in the presence of HNTs. We observe that the extent of RhB photocatalytic degradation in 100 min in the presence of the HNTs is ~four times higher compared to that of bare RhB. Moreover, under optimized conditions, the as-extracted photodegradation rate of RhB (~0.0022 min−1) is comparable to that of the previously reported work on the photodegradation of RhB in the presence of tubular nanostructures. A parallel effect is observed for anionic Coumarin photodegradation, albeit less efficiently. Our analysis attributes this discrepancy to the distinct charge states of the two dyes, influencing their attachment sites on HNTs. Cationic Rhodamine B molecules preferentially attach to the outer surface of HNTs, while anionic Coumarin molecules tend to attach to the inner surface. By leveraging the unique properties of HNTs, a family of naturally occurring nanotube structures, this research offers valuable insights for optimizing photocatalytic systems in the pursuit of effective and eco-friendly solutions for environmental remediation.

MoSe2 in flower spheres provides abundant active sites for TiO2 photocatalytic degradation of RhB

In this paper, a MoSe2/TiO2 composite photocatalyst was constructed by modifying TiO2 with MoSe2 as a group catalyst. The results showed that pure TiO2 and MoSe2 had no degradation activity for RhB, and the composite catalyst of 0.03 g MoSe2 had the best photocatalytic degradation activity for RhB. Through SEM, TEM, UV-VIS absorption spectrum, transient photocurrent curve, photoluminescence spectrum, and electrochemical impedance spectrum analysis, it can be seen that the excellent performance of 0.03 g MoSe2 composite sample is due to its excellent nanostructure, and uniform TiO2 nanosheets are attached to MoSe2 flower spheres. The active site of RhB photocatalytic degradation was increased, the visible light response and photobiological carrier separation were enhanced, and TiO2 had photocatalytic activity under simulated sunlight.

Construction of carbon-doped mesoporous g-C3N4 catalytic nanoreactor via bubble template method for visible-light photocatalysis

Morphological control of photocatalysts is an important way to improve photocatalytic activity. Herein, we design a carbon-doped mesoporous g-C3N4 nanoreactor by combining the self-assembly method of supramolecular precursors with the bubble template method. The mesoporous structure can increase the utilization rate of light absorption. Furthermore, the C atoms replace the position of bridging N atoms may generate delocalized large π bonds, both of which can facilitate photocatalysis. This nanoreactor coupled with larger specific surface area and faster electronic transmission efficiency shows an outstanding performance in photocatalytic RhB degradation (97%, 15 min) and reducing CO2 into CO (60.82 μmol/g, 5h). The C-doped mesoporous g-C3N4 nanoreactor would provide some practical reference for environmental improvements and clean energy production.

Band engineering of single-halogen layered Sillén oxyhalide, BaBiO2X (X = Cl, Br, and I): The role of lone-pair effect in photocatalysts

Band structure engineering is an effective way to improve the performance of photocatalysis. Herein, layered oxyhalides, BaBiO2X (X = Cl, Br, and I), with single halogen layers were synthesized by using molten salt synthesis method. Density functional theory (DFT) calculation reveals that the valance band maximum (VBM) of BaBiO2X mainly consists of O 2p orbitals, not halogen p orbitals (Cl-3p, Br-4p, and I-5p), which means that this X1 oxyhalide owns the stability against self-degradation by photogenerated holes during the photocatalytic process. Simultaneously, with the increasing of atomic number from BaBiO2Cl to BaBiO2I, the band gap (Eg) decreases from 3.523 eV to 2.777 eV. Eventually, BaBiO2I exhibits the highest photocatalytic RhB degradation performance among all samples, mostly owning to the enhanced light absorption and improved separation and migration efficiency of photogenerated carriers. This study provides a new idea for designing bismuth-based photocatalysts by band engineering to solve environmental pollution.

G-C3N4/In2O3 heterojunction films and their excellent photocatalytic performance in fruit preservation and organic dye degradation

We prepared g-C3N4/In2O3 composite films on the wire mesh of stainless steel by a hydrothermal method combined with annealing. XRD, SEM, and XPS results confirmed the heterojunction formation of g-C3N4/In2O3. UV–vis spectroscopy showed that the heterojunction films exhibited enhanced visible light absorption capacity compared with the pristine In2O3 films. Compared with the individual In2O3 films, the PL intensity of the g-C3N4/In2O3 composite films was remarkably reduced, their photocurrent density was significantly increased, and the semicircle in EIS plots was reduced. All the above changes are attributed to the heterojunction formation between g-C3N4 and In2O3. According to our proposed mechanism, photogenerated electrons transfer from g-C3N4 to In2O3 while the holes move in the opposite direction. Therefore, the spatial transfer and separation of photoinduced electrons and holes was achieved. In other words, the recombination efficiency of photogenerated electrons and holes was remarkably suppressed. In photocatalytic RhB degradation, g-C3N4/In2O3 heterojunction films exhibited much higher photocatalytic activity than the pristine In2O3 films. In our self-made photocatalytic fruit-preservation system, these g-C3N4/In2O3 heterojunction films showed excellent fruit preservation ability. Specifically, the bananas remained turquoise green without turning yellow or black spots, even black patches, after a seven-day evaluation period.

Effect of pH on the photo-Fenton degradation of rhodamine B by Prussian blue/g-C<sub>3</sub>N<sub>4</sub>

The pH solution is one of the critical factors affecting the photo-Fenton degradation of dyes in wastewater. The photoactivity of Prussian blue/g-C3N4 was investigated using the photodegradation of RhB acidic, neutral, and essential medium. The results implicated that more than 98.5% removal of RhB was achieved at pH = 3.62 after irradiation for 60 minutes under visible light. The photocatalytic activity of Prussian blue/g-C3N4 showed the best performance in an acidic medium. This is due to the formation of hydroxyl radicals during the photocatalytic degradation of RhB. Thus, this study has shown the role and potential of the application of photocatalysts in the degradation of toxic organic compounds the wastewater.

Green fabrication of CuO-egTiO2 composite for photodegradation of organic pollutant under direct visible light illumination

A (CuO-egTiO2) composite coated with copper oxide has been manufactured as a green and facile photocatalyst via Argyreia nervosa leaf extract. The photocatalyst consists of equaixial geometry (egTiO2) particles with copper oxide (CuO) nanocrystals deposited on the TiO2 surface in varying proportions. The structural, morphological, and optical properties of the CuO-egTiO2 photocatalyst nanostructures were inspected via various techniques, through (XRD), (FE-SEM), (DRS), (BET) analysis, (PL) spectra, and (TEM). The results obtained revealed the non-uniform growth of CuO nanocrystals on the surface of TiO2 particles, resembling a (core–shell) structure. The photocatalytic activity of the CuO-egTiO2 nanocomposite was verified in the degradation of Rhodamine B dye (RhB) using an inhomogeneous photocatalytic activation process, with CuO-egTiO2 (10 %) proving to be the most effective photocatalyst under visible light. The effect of the catalyst quantity within concentrations of 0.3–1.8 g/L was studied by exposing aqueous solutions containing the photocatalysts to visible radiation. The dye removal rate was estimated by calculating the remaining concentration, indicating a pseudo-first-order disappearance model with a dye removal percentage of 95.20 %. Additionally, the impact of reactive oxygen species (ROS) types was investigated, The highest photocatalytic degradation rate of 52.16 % was observed when using the inhibitor (EDTA), indicating that the active group contributing to the photocatalytic degradation of RhB is hydroxyl radicals (●OH). At last, in reuse experiments, it was demonstrated that the CuO-egTiO2 (10 %) photocatalyst maintained a remarkable 75.3 % of its initial efficiency even after being recycled for four cycles.

Construction of Z-type Bi12O15Cl6/Ag2CO3 photocatalyst for enhanced photocatalytic degradation of RhB and TC

Construction of Z-type Bi12O15Cl6/Ag2CO3 photocatalyst for enhanced photocatalytic degradation of RhB and TC

Amorphous LaWOx nanoparticles with rich O defects for photocatalytic RhB degradation

Water containing organic pollutants is posing an increasingly serious challenge to the clean water resources on which human beings depend. As a promising environmental purification technology, photocatalytic degradation can directly use solar energy to purify polluted wastewater without any secondary pollution. Synthesized via the wet chemical method, LaWOx nanoparticles display ultraviolet light responsiveness, large surface area, amorphous features, and abundant surface oxygen defects. These characteristics empower LaWOx NPs to efficiently degrade Rhodamine B, achieving a 92.76 % degradation efficiency in 105 min and a rate constant (Kap) of 0.02215 min−1 under full-spectrum irradiation. This study offers insights into developing new amorphous nano-photocatalysts.

Synthesis of Efficient S-Scheme Heterostructures Composed of BiPO4 and KNbO3 for Photocatalytic N2 Fixation and Water Purification.

The preparation of catalysts with heterojunction structures is a strategy to achieve efficient charge separation and high photocatalytic activity of photocatalysts. In this work, BiPO4/KNbO3 heterostructure photocatalysts were fabricated by a combination of hydrothermal and precipitation methods and subsequently employed in catalyzing N2-to-NH3 conversion and RhB degradation under light illumination. Morphological analysis revealed the effective dispersion of BiPO4 on KNbO3 nanocubes. Band structure analysis suggests that KNbO3 and BiPO4 exhibit suitable band potentials to form an S-scheme heterojunction. Under the joint action of the built-in electric field at the interface, energy band bending, and Coulomb attraction force, photogenerated electrons and holes with low redox performance are consumed, while those with high redox performance are effectively spatially separated. Consequently, the BiPO4/KNbO3 shows enhanced photocatalytic activity. The NH3 production rate of the optimal sample is 2.6 and 5.8 times higher than that of KNbO3 and BiPO4, respectively. The enhanced photoactivity of BiPO4/KNbO3 is also observed in the photocatalytic degradation of RhB. This study offers valuable insights for the design and preparation of S-scheme heterojunction photocatalysts.

Redeeming the photocatalytic potential of CuWO4 incorporating Ag6Si2O7 via S-scheme PN heterostructure

Water pollution and energy crisis are deemed the most prevalent issues of contemporary decades, and enhanced efforts to counteract these issues via semiconductor photocatalyst engineering are among the best-proposed solutions. Semiconductor photocatalysts could effectively transform clean sunlight into chemical energy, thereby facilitating the breakdown of organic dyes. Herein, we demonstrate the PN heterojunction S scheme photocatalyst Ag6Si2O7/CuWO4 via the facile hydrothermal method. The Ag6Si2O7/CuWO4 heterostructure discerns the broadening of the absorption spectrum and enhanced carrier separation owing to the interfacial process at the interface. Both these aspects work as a stimulus regarding the photocatalytic properties and add versatilities to the effective utilization of carriers. The performance of different ratios of Ag6Si2O7 and CuWO4 in Ag6Si2O7/CuWO4 composite was monitored via photocatalytic degradation of Rhodamine B and Methylene Blue under visible irradiation. About 97.50% degradation efficiency for RhB was reached in 50 minutes at a 1:5 molar ratio (AgCW-E). The degradation constant rate of AgCW-E for RhB and MB was 21.12 and 26.13 times higher than pristine, respectively. Based on trapping experiments and electron spin resonance spectra, it was determined that the photogenerated holes (h+) and •O2- played a crucial role as active species in the photocatalytic degradation of RhB. The synthetic substances additionally demonstrated great promise for recycling. The present study delivers an innovative perspective on developing a more potent Ag6Si2O7/ CuWO4 nano heterojunction photocatalyst that can capture visible light.

Ag/α-Fe2O3/g-C3N4 nanocomposites as Z-scheme heterojunction photocatalysts for degradation of RhB

In this study, Ag/α-Fe2O3/g-C3N4 composites with varying α-Fe2O3 and Ag contents were synthesized by loading α-Fe2O3 and Ag nanoparticles onto the g-C3N4 with a high specific surface area via acid annealing. These composites were then utilized for the photocatalytic degradation of RhB under the irradiation of visible light. For α-Fe2O3/g-C3N4 composites with 5 wt% content of α-Fe2O3, the degradation efficiency reached a peak of 97.57% within 55 min, which was much higher than that of α-Fe2O3 and acid-annealed g-C3N4 with 45.92% and 83.61%, respectively. Furthermore, the photocatalytic degradation efficiency of Ag/α-Fe2O3/g-C3N4 composites reached its maximum of 99.61% with 1% content of Ag. It was demonstrated that the ternary Z-scheme heterojunction construction leaded to a significant enhancement of carrier separation and transfer effects, while the incorporation of Ag serves as electron reservoirs and photoinduced electrons capturers, thereby significantly enhancing the Fenton reaction and photocatalytic performance. This work is significant to drive the widespread application of g-C3N4 based heterojunctions in photocatalytic water purification.

Enhanced photocatalytic degradation by higher exposure of {110} facet and surface oxygen vacancies of BiOBr through cobalt doping strategy

Transition metal cobalt doped BiOBr (Co-BOB) was successfully synthesized by using hydrothermal method. The optimized Co-BOB achieved a remarkable rhodamine B degradation rate of 97 % in 30 min under visible light irradiation when initial concentration was 80 mg·L−1. Satisfactory removal efficiency was also observed under ambient sunlight irradiation and various water conditions. The cobalt doping strategy induced abundant surface oxygen vacancies formation (43.22 %) and resulted in an increasing exposure of {110} facets. The photosensitization and photocatalytic activities of Co-BOB significantly enhanced comparing with that of pure BiOBr. The synergy of Co doping and oxygen vacancies also induced the formation of a new band structure in Co-BOB. The synergistic effect promoted the efficient separation of photogenerated electrons and holes. By combining with density functional theory calculation, the RhB photocatalytic degradation mechanism by Co-BOB was proposed.

A novel layered double hydroxide-based ternary nanocomposite for the effective photocatalytic degradation of rhodamine B.

Photocatalytic degradation of organic pollutants is a green and effective route of wastewater treatment. Zinc oxide was initially used for this purpose; however, calcined zinc/chromium layered double hydroxide (ZnCr-LDO) and cadmium sulfide quantum dots (CdSQDs)-based nanocomposites proved as superior alternatives. Herein, we report a green sonochemical method for the sol-gel fabrication of novel CdSQDs@ZnCr-LDO/ZnO ternary nanocomposite that exhibited exceptional photocatalytic activity for the degradation of rhodamine B dye (RhB), in wastewaters, under UV-A-irradiation. The features of the ternary nanocomposite were investigated using various physicochemical techniques, including XRD, SEM, TEM, EDX, XPS, BET, zeta potential, DRS, and PL measurements. The RhB dye % removal was 38.02, 40.2, and 98% using pristine ZnO, ZnCr-LDO and the ternary CdSQDs@ZnCr-LDO/ZnO-based nanomaterials, respectively, reflecting the superior ternary nanocomposite's photocatalytic activity that made it an excellent competitor to commonly reported photocatalysts. Additionally, an investigation was carried out to determine the key reactive species in the photocatalytic degradation of RhB, considering both scavenger's type and concentration. The prevailing mechanism was found to be the reductive photodegradation pathway. Furthermore, several models were utilized to describe the kinetics of photocatalytic performance of the ternary nanocomposite and a typical Z-scheme type-II photocatalytic heterojunction mechanism was inferred.

Design of interfacial dual Schottky junctions to modulate charge transfer for enhanced piezo-assisted photocatalytic degradation RhB performances

Construction of piezo-assisted interfacial dual Schottky junction to regulate charge transfer and surface reaction rate for the photocatalytic degradation of RhB.

Dual-functional, highly efficient CaIn2S4/PDA@SnO2 photocatalyst with Z-Scheme for photocatalytic hydrogen production from water splitting and organic pollutant degradation

Heterojunction can be used to develop semiconductor catalysts with high photocatalytic activity. In this work, a Z-Scheme CaIn2S4(CIS)/PDA@SnO2 photocatalyst was successfully synthesized. Firstly, SnO2 hollow nanospheres were prepared by hydrothermal method. On this basis, SnO2 hollow nanospheres wrapped by polydopamine (PDA) were obtained via self-polymerization of dopamine. Finally, the CIS/PDA@SnO2 composites were synthesized via a one-step oil bath method. The heterojunction has successfully achieved effective separation of electron-hole pairs. PDA acted as a photosensitizer and an electron transfer medium in the heterojunction. Multiple characterization techniques such as XRD, SEM, TEM, BET, XPS, PL, UV–vis DRS, EPR and photoelectrochemical measurements were used for material structure and performance analysis. The photocatalytic performance of the photocatalysts was tested by photocatalytic hydrogen production from water splitting and RhB solution degradation. A flower-like close contact between CaIn2S4 and PDA@SnO2 interfaces can be obviously observed via SEM and TEM images. The band gap energies (Eg) of CaIn2S4 and PDA@SnO2 are 2.06 eV and 3.74 eV. CaIn2S4/PDA@SnO2-1(CPS-1) exhibits stronger light absorption together with lower transfer resistance compared to other samples. CPS-1 showed excellent photocatalytic hydrogen production and RhB degradation performance. Furthermore, the results of active species capture experiments, Mott-Schottky curve, XPS measurement and other tests show that it is logical to use the Z-Scheme charge mobility process to explain the better photocatalytic activity of the CIS/PDA@SnO2 composite. This work will present an efficient option for the fabrication of Z-Scheme heterojunctions and possibly further develop a new avenue for the control of the structure of semiconductor photocatalysts.

Synthesis of novel ZnIn0.2Ga1.8O4/CaIn2S4 composite material with S-scheme heterojunction for efficient photocatalytic degradation of organic pollutants and hydrogen evolution

Semiconductor photocatalysts that can both photocatalytic evolve hydrogen from water and degrade organic pollutants are very important to solve the problem of energy shortage and environmental pollution. The S-scheme ZnIn0.2Ga1.8O4/CaIn2S4 complex was successfully synthesized using sol–gel and oil bath methods. Characterization technique indicates that chrysanthemum-shaped CaIn2S4 is anchored on the surface of irregular nanoparticles ZnIn0.2Ga1.8O4, forming a closely packed heterostructure. The bandgap values of CaIn2S4 and Zn(In0.1Ga0.9)2O4 were determined as 2.11 eV and 3.61 eV, respectively. Under visible-light irradiation, the ZnIn0.2Ga1.8O4/CaIn2S4-1(ZC-1) photocatalyst exhibited superior performance in degrading an organic pollutant (RhB) and generating hydrogen compared to ZnGa2O4, ZnIn0.2Ga1.8O4, and CaIn2S4 alone. The photocatalytic degradation of RhB using ZC-1 was 1.7, 1.31, and 1.14 times higher than that of ZnGa2O4, ZnIn0.2Ga1.8O4, and CaIn2S4, respectively. Moreover, the photocatalytic hydrogen evolution rate of ZC-1 was 5.8, 3.7, and 13 times higher than that of ZnGa2O4, ZnIn0.2Ga1.8O4, and CaIn2S4, respectively. The formation of S-type heterojunctions in the composite photocatalysts was confirmed through free radical trapping and electron paramagnetic resonance tests, further enhancing hydrogen production and organic pollutant degradation. This study presents a novel approach for developing ZnGa2O4-based composite photocatalysts with S-scheme heterojunctions to address energy shortage and environmental pollution in the future.

Type II Heterojunction Formed by 3D Flower-like Microspheres of BiOBr/NH2–Fe-MOF with High Photocatalytic Degradation of RhB via Visible Light

Type II Heterojunction Formed by 3D Flower-like Microspheres of BiOBr/NH₂–Fe-MOF with High Photocatalytic Degradation of RhB via Visible Light