Recombination Of Photogenerated Carriers Research Articles

Controlling size and distribution of Au nano-particles on C3N4 for high-efficiency photocatalytic hydrogen production.

With advantages such as low cost, high stability, and ease of production, visible light photocatalytic C3N4 with a unique microscopic layered structure holds significant potential for development. However, its hydrogen production efficiency remains low due to the pronounced recombination of photo-generated charge carriers and limited surface reaction sites. Normally, the photocatalytic performance of C3N4 can be enhanced by loading noble metals with surface plasmon resonance. It is worth noting that the size of noble metal nanoparticles has a great influence on photocatalytic performance. In this study, accurate controlling of the size and distribution of Au nanoparticles was achieved on the surface of C3N4 by introducing amino groups to improve photocatalytic performance. Results show that uniformly distributed Au nanoparticles in the range of 2-6nm can be obtained on C3N4 with a remarkable enhancement of hydrogen production efficiency, which is about 114 times the property of pure C3N4. The small-sized and uniformly distributed Au nanoparticles can provide more reaction sites and increase the separation of photo-generated charge carriers, in turn improving Au/NH3-C3N4 photocatalytic hydrogen release rate to 6.85 mmol g-1h-1. This work offers a facile way to enhance photocatalytic performance by controlling the size of metal nanoparticles on C3N4 precisely.

Integration of Perylene Diimide into a Covalent Organic Framework for Photocatalytic Oxidation.

Perylene diimides (PDIs) have garnered considerable attention due to its immense potential in photocatalysis. However, manipulating the molecular packing within their aggregates and enhancing the efficiency of photogenerated carrier recombination remain significant challenges. In this study, we demonstrate the incorporation of a PDI unit into a covalent organic framework (COF), named PDI-PDA, by linking an ortho-substituted PDI with p-phenylenediamine (PDA) to control its intermolecular aggregation. The incorporation enables precise modulation of electron transfer dynamics, leading to a ten-fold increase in the efficiency of photocatalytic oxidation of thioether to sulfoxide with PDI-PDA compared to the PDI molecular counterpart, achieving yields exceeding 90%. Electron property studies and density functional theory calculations show that the PDI-PDA with its well-defined crystal structure, enhances π-π stacking and lowers the electron transition barrier. Moreover, the strong electron-withdrawing ability of the PDI unit promotes the spatial separation of the valency band maximum and conduction band minimum of PDI-PDA suppressing the rapid recombination of photogenerated electron-hole pairs and improving charge separation efficiency to give high photocatalytic efficiency. This study provides a brief yet effective way for the improvement of the photocatalytic efficiency of commonly used PDI-based dyes by integrating them into a framework skeleton.

Integration of Perylene Diimide into a Covalent Organic Framework for Photocatalytic Oxidation

AbstractPerylene diimides (PDIs) have garnered considerable attention due to their immense potential in photocatalysis. However, manipulating the molecular packing within their aggregates and enhancing the efficiency of photogenerated carrier recombination remain significant challenges. In this study, we demonstrate the incorporation of a PDI unit into a covalent organic framework (COF), named PDI‐PDA, by linking an ortho‐substituted PDI with p‐phenylenediamine (PDA) to control its intermolecular aggregation. The incorporation enables precise modulation of electron‐transfer dynamics, leading to a ten‐fold increase in the efficiency of photocatalytic oxidation of thioether to sulfoxide with PDI‐PDA compared to the PDI molecular counterpart, with yields exceeding 90 %. Electron property studies and density functional theory calculations show that the PDI‐PDA with its well‐defined crystal structure, enhances π–π stacking and lowers the electron transition barrier. Moreover, the strong electron‐withdrawing ability of the PDI unit promotes the spatial separation of the valency band maximum and conduction band minimum of PDI‐PDA, suppressing the rapid recombination of photogenerated electron‐hole pairs and improving the charge‐separation efficiency to give high photocatalytic efficiency. This study provides a brief but effective way for improving the photocatalytic efficiency of commonly used PDI‐based dyes by integrating them into a framework skeleton.

Interface passivation treatment enables GaAs/CNT heterojunction solar cells over 19 % efficiency

Without interface passivation, few technologies have realized carbon material-based GaAs heterojunction solar cells (HJSCs) with high power conversion efficiency (PCE) and long-term stability. Here, inorganic hole transport materials, such as CuSCN and CuI, were first created to address the issue of interface photo-generated carrier recombination in GaAs/carbon nanotube (CNT) HJSCs. The application of CuSCN and CuI passivation layer enables the PCE of GaAs/CNT HJSCs to be improved from 8.53 % to 17.22 % and 12.48 %, respectively. Furthermore, by employing the multifunctional WO3 film, which can serve simultaneously as a hole-blocking layer and an anti-reflection coating, to construct a collaborative optimization system, the cell performance can be further enhanced to 19.06 % and 15.53 %, respectively. Additionally, their stability has been significantly enhanced to 98.11 % and 111.5 %, respectively, which are much higher than that of the pristine HJSC (8.53 %). Especially, the high quality of Cu+-based passivation layer affords a fill factor (FF) of 80.21 %, which is a record for GaAs-based HJSCs. This work is a breakthrough as it presents a pioneering cross-generational concept for addressing the poor stability performance of carbon materials-based HJSCs.

Z-scheme flower-like Ag/AgCl/NiZnAl-LDH for high efficiency removal of Methylene Blue: Performance and mechanism insights

3D flower-like NiZnAl-LDH was prepared, and then the Z-scheme Ag/AgCl/NiZnAl-LDH heterojunctions were further constructed by loading different amounts of AgCl on NiZnAl-LDH surface. The structure, morphology and photoelectric properties were characterized by a variety of advanced techniques, such as XRD, XPS, SEM, HRTEM and EIS. Furthermore, methylene blue, abbreviated MB, was used as the target pollutant, and the photocatalytic degradation activity of Ag/AgCl/NiZnAl-LDH on it was explored. Results displayed that the Ag/AgCl/NiZnAl-LDH photocatalysts displayed excellent photocatalytic degradation activity for MB dye compared with AgCl and NiZnAl-LDH, and the loading of different AgCl on the surface of NiZnAl-LDH has a considerable influence on the photocatalytic performance. The alkaline condition and low concentration of MB are more conducive to the photocatalytic degradation of MB by Ag/AgCl/NiZnAl-LDH. The photocatalytic process conforms to the first-order kinetic model with a rate constant of 0.0082 min−1, which is about 3.4 times that of AgCl and NiZnAl-LDH. Compared with AgCl and NiZnAl-LDH, it is found that Ag/AgCl/NiZnAl-LDH increases the separation rate of photogenerated electrons and holes, the photogenerated carrier recombination is inhibited, and the electrochemically active area is increased. The outstanding photocatalytic activity and stability make Ag/AgCl/NiZnAl-LDH a perfect material to ease the environmental crisis. Besides, combined with free radical trapping experiments, a possible photocatalytic mechanism was raised.

Nanoarchitectonics of MIL-101(Fe)/g-C3N4 S-Scheme heterojunction for photocatalytic nitrogen fixation: Mechanisms and performance

Recently, there has been a growing interest in the fundamental understanding of the mechanism of how MIL-101(Fe)/g-C3N4 heterojunctions facilitate the occurrence of photocatalytic nitrogen fixation reactions, especially the electron transfer mechanism has attained increasing attention in photocatalysis. Herein, we implemented a "triple win scenario" strategy to fabricate the S-scheme MIL-101(Fe)/g-C3N4 heterojunction through a straightforward solvothermal process. The MC-6 heterojunction minimizes the recombination of photogenerated carriers, enhances light utilization efficiency, and activates the N≡N bond, thus boosting photocatalytic nitrogen fixation efficiency. The transition metal iron activates the N≡N bond, while S-scheme heterojunctions reduce the photogenerated carrier recombination. In addition, the decrease in band gap (Eg) leads to an increase in visible light utilization efficiency. ISIXPS proved the mechanism of interelectron transfer of MIL-101(Fe)/g-C3N4 heterojunction under illumination. Upon the creation of the heterojunction, electrons migrate from g-C3N4 to MIL-101(Fe), establishing an inherent electric field due to the disparate Fermi levels between the two materials. The electrons (e-) on the g-C3N4 CB with a more negative reduction potential and the holes (h+) on the MIL-101(Fe) VB are retained, which increased the redox capacity to a great extent required for the reduction of N2 to NH3. The ammonia production efficiency of MC-6 photocatalyst was 160 µmol gcat-1 h-1, representing an 8-fold and 2.8-fold improvement over pristine g-C3N4 (20 µmol gcat-1 h-1) and MIL-101(Fe) (57 µmol gcat-1 h-1), respectively.

Nanosecond laser annealing processed surface-structured hyperdoped silicon for efficient near-infrared detection

Surface-structured engineering of hyperdoped silicon can effectively facilitate the absorption of sub-bandgap photons in pristine single-crystal silicon (sc-Si). Here, we conducted different annealing approaches of ordinary thermal annealing (OTA) and nanosecond laser annealing (NLA) on modification of titanium-hyperdoped silicon (Si:Ti) surface structure, to achieve efficient near-infrared detection. It is presented that both OTA and NLA processes can improve the crystallinity of Si:Ti samples. In detail, atomic-resolved STEM characterization illustrates that NLA treatment will further eliminate the amorphous phase on Si:Ti surface to varying degrees. While one-dimensional periodic stacking fault structure of 9R-Si phase is formed at the surface of sc-Si and embedded in the Si matrix during the OTA process, which reveals the seamless interface of 9R-Si/sc-Si along with [11¯0] direction. Due to the high sub-bandgap light absorption and good crystal structure, the Si:Ti photodetector after NLA treatment with an energy density of 2.6 J cm-2exhibited the highest responsivity, reaching 151 mA W-1at 1550 nm even at a low operating voltage of 1 V. We assume the performance enhancement of NLA processed Si:Ti photodetectors can be attributed to two aspects, the one is NLA can reduce the recombination of photo-generated charge carriers in amorphous surface layer by improving crystallization, and the other is that NLA process can weaken the diffusion of titanium impurities due to the extremely rapid heating and cooling rates. This study presents prospects towards surface-structured silicon in infrared light detection.

2D Gr/WSe2/MoTe2 vertical heterojunction for self-powered photodiode with ultrafast response and high sensitivity

Two-dimensional materials without lattice constraints can be combined into form heterojunctions via van der Waals forces, providing opportunities for the future development of novel high-performance photodetectors. In non-vertical heterojunction devices with long carrier transport channels, SRH recombination due to defect and interface states in the heterojunction and Langevin recombination due to Coulomb interactions induce large amounts of photogenerated carrier recombination, leading to low quantum efficiencies of the heterojunction. At the same time, defect and interface trap states, as well as the long channel of the non-vertical heterojunction device, lead to a slow response speed of the device. In this work, a 2D WSe2/MoTe2 vertical heterojunction photodiode with a transparent graphene top electrode has been designed to simultaneously achieve high sensitivity and fast response speed of photodetectors. Benefiting from the vertical device structure, high-quality interface and low contact resistance, the photogenerated electron-hole pairs can be efficiently separated and transported. The photodiode exhibits remarkable rectification characteristics with a rectification ratio as high as 1.4 × 104, and provides a broadband and self-powered photodetection from the visible to NIR bands (405–1064 nm) with a maximum responsivity of 0.33 A/W at 785 nm. In particular, the photodiode achieves an ultra-fast rise/fall time of 6.49/6.22 μs at 0 V and a further reduction of the response time to 1.68/1.2 μs at a reverse bias of −1 V. This ultra-fast response allows the photodiode to detect switching signals with a cutoff frequency of more than 70 kHz and 200 kHz at 0 V and −1 V, respectively. This work opens up new opportunities for the development of integrated 2D photodetectors with low power consumption, high sensitivity, and high speed.

Construction of CdS nanosphere with rare earth metal modification over acid theory with boosted photocatalytic hydrogen reaction

Absorption of light, surface reaction and carriers transfer are three main aspects that affect the whole photocatalytic process and activity. Surface modification strategy is widely adopted to promote the light response while still presented poor carriers transfer. Therefore, rare earth metal was introduced to regulate the surface property of the photocatalyst, which shows enhanced photocatalytic performance of 4567.0 μmol h−1 g−1 under optimal rare earth doping compare to 1553.3 μmol h−1 g−1 of pure CdS. The addition of Gd could expose more reactive centers and reduce the recombination of photo-generated carriers. Meanwhile, the doping of Gd could extend the light absorption and accelerate the hydrogen production kinetics.

In Situ Growth of CdS Nanoparticles Between g‐C3N4 Layers for Photocatalytic Reduction of Nitrobenzene

AbstractPhotocatalysis technology is green and sustainable for reduction of nitrobenzene to aniline. However, the photocatalytic activity of pure carbon nitride is limited by the high photogenerated carrier recombination rates. Carbon nitride nanosheets (CNN) were prepared by prepolymerization and high temperature calcination and cadmium sulfide (CdS) nanoparticles were in situ grown between the layers of carbon nitride for facilitating the separation and transfer of charges. As a result, the optimal composite catalyst (CdS/CNN‐2) exhibited superior photocatalytic activity with nitrobenzene reduction rate of 83 % within 60 min. This work presents an effective strategy for designing catalysts for the photocatalytic reduction of nitrobenzene.

Identifying the effect of photo-generated carriers on the phonons in rutile TiO2 through Raman spectroscopy

Abstract Investigating lattice vibrations through Raman spectroscopy is a crucial method for studying crystalline materials. Carriers can interact with lattices and influence lattice vibrations; thus, it is feasible to study the effect of photo-generated carriers on phonons by analyzing changes in the Raman spectra of semiconductors. Rutile is one of the predominant crystalline phases of TiO2, which is a widely utilized metal oxide semiconductor. In this work, rutile TiO2 is coated on thinned optical fiber to concentrate ultraviolet light energy within the material, thereby enhancing the generation of carriers and amplifying the changes in the Raman spectra. Raman detection laser with a wavelength of 532 nm is utilized to collect the Raman spectra of rutile TiO2 during irradiation. Using this setup, the impact of photo-generated carriers on the phonons corresponding to Raman vibrational modes is researched. The localization and non-radiative recombination of photo-generated carriers contribute to a reduction in both the frequencies and lifetimes of phonons. This work provides a novel approach for researching the effect of carriers on phonons.

Hollow TiO2/Bi2MoO6 Janus-nanofibers for photo-reforming of antibiotics into carbon monoxide

Photo-reforming is an environmentally friendly technology for converting organic wastewater into carbon monoxide (CO), a potential energy source and an important industrial material. Achieving efficient photo-reforming of CO production remains a challenge due to the limitation on fast photogenerated carrier recombination. Here, the TiO2/Bi2MoO6 hetero-nanofibers are well-designed to possess unique Janus interface and ingenious hollow structure. The photo-deposition experiments demonstrated that the Janus binary interface can realize the directional migration of interfacial charges and the spatial separation of redox sites. Moreover, the hollow framework allows full exposure of the bicomponent to reactants and provides excellent optical absorption through multiple light scattering inside the tube, as evidenced by theoretical simulations via COMSOL Multiphysics. The photo-reforming yield of CO from 6000 ppm tetracycline hydrochloride (TCH) solution reaches 2.69 μmol∙g−1∙h−1 (corresponding degradation rate of 44.55 % after 5 h), about 1.44-fold superior to that of the TiO2/Bi2MoO6 core-shell hetero-nanofibers. 13C isotope tracing experiments showed that the efficiency of CO production in the photocatalytic TCH oxidation process is superior to that in carbon dioxide reduction process. Furthermore, when oxygen was introduced into the photocatalytic system, the photo-reforming CO yield from the TCH solution was significantly increased to 60.45 μmol∙g−1∙h−1, which was 22.47 and 5.12 times higher than in carbon dioxide and air atmosphere, respectively. This work provides a promising interfacial engineering to design efficient photo-reforming catalysts for energy production and environmental remediation.

In situ XPS confirms enhanced hydrogen evolution in S-scheme heterojunction Cd0.8Mn0.2S/Cu2WS4 via charge vectorial separation

Solar-driven water splitting for hydrogen production is a vital approach to mitigating the energy crisis and achieving carbon neutrality and peak carbon emissions. Cd0.8Mn0.2S holds significant potential for photocatalytic hydrogen evolution but faces severe challenges due to photogenerated carrier recombination. To address this, we employed ultrasonic self-assembly to tightly couple Cu2WS4 nanosheets with Cd0.8Mn0.2S nanoparticles, forming an S-scheme heterojunction to reduce carrier recombination rates. In this configuration, Cd0.8Mn0.2S acts as the electron acceptor, and Cu2WS4 serves as the electron donor. The Cd0.8Mn0.2S/Cu2WS4 structure creates a closely spaced interface, providing the shortest transfer distance for electron migration. The S-scheme heterojunction strategy effectively suppresses the recombination of photogenerated carriers, promoting vectorial separation. Under 10 W white light irradiation, the Cd0.8Mn0.2S/Cu2WS4 composite photocatalyst exhibited remarkable hydrogen evolution activity, with a hydrogen production rate of 39.83 mmol g−1 h−1. This S-scheme heterojunction strategy lays the foundation for the structural design and large-scale application of high-activity visible-light photocatalysts.

Janus NbOBrI monolayer for efficient photocatalytic overall water splitting

Due to the presence of a built-in electric field, two-dimensional Janus materials can effectively reduce photogenerated carrier recombination while promoting carrier separation. In this work, the viability of Janus NbOBrI monolayer as a high-efficiency photocatalyst for water splitting was examined using first-principles calculations. The results demonstrate that the Janus NbOBrI monolayer exhibits appropriate band-edge potentials, significant visible light absorptions, high carrier separation efficiency and high enough carrier mobility along the Peierls distortion direction. Moreover, we have determined the variations in the Gibbs free energy for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) at various pHs, and found that the OER can occur spontaneously in the light environment. Applying -1.5 % uniaxial strain in the a(b) direction of the NbOBrI monolayer helps to increase the reduction potential and provide sufficient power for the HER, resulting in a solar-to-hydrogen (STH) efficiency of 8.9 % (9.3 %).

Multi-active photocatalysts of biochar-doped g-C3N4 incorporated with polyoxometalates for the high-efficient degradation of sulfamethoxazole

Sulfamethoxazole (SMX) is one of major antibiotic contaminants in current aqueous environment. In this paper, waste loofah and melamine were co-carbonized to prepare biochar-doped g-C3N4 (CCN) by a one-pot method and then combined with Co2PMo11VO40 (CoPMoV) using a binder to obtain the novel polyoxometalates (POMs) photocatalytic composites (CCN/CoPMoV). The incorporation of CoPMoV dramatically reduced the photogenerated carrier recombination and led to a small band gap. Under visible light, the synergetic activation from biochar, g-C3N4 and POMs can remove 98.5% of SMX (k = 0.215 min−1) in the peroxymonosulfate (PMS) system within 20 min and keep its high stability with the degradation of 88.9% after five cycles. Multi-active sites from CCN/CoPMoV are contributed to develop the most active species of SO4−∙, ·OH, 1O2, and h+. The validity in the degradation of SMX makes CCN/CoPMoV a promising and potential material for the removal of aqueous pollutants in the future.

Constructing Metal-Organic Framework Films with Adjustable Electronic Properties on Hematite Photoanode for Boosting Photogenerated Carrier Transport.

Hematite (α-Fe2O3) has become a research hotspot in the field of photoelectrochemical water splitting (PEC-WS), but the low photogenerated carrier separation efficiency limits further application. The electronic structure regulation, such as element doping and organic functional groups with different electrical properties, is applied to alleviate the problems of poor electrical conductivity, interface defects, and band mismatch. Herein, α-Fe2O3 photoanodes are modified to regulate their electric structures and improve photogenerated carrier transport by the bimetallic metal-organic frameworks (MOFs), which are constructed with Fe/Ni and terephthalate (BDC) with 2-substitution of different organic functional groups (─H, ─Br, ─NO2 and ─NH2). The α-Fe2O3 photoanode loaded with FeNi-NH2BDC MOF catalyst exhibits the optimal photocurrent density (2mAcm-2) at 1.23VRHE, which is 2.33 times that of the pure α-Fe2O3 photoanode. The detailed PEC analyses demonstrate that the bimetallic synergistic effect between Fe and Ni can improve the conductivity and inhibit the photogenerated carrier recombination of α-Fe2O3 photoanodes. The ─NH2 group as an electron-donor group can effectively regulate the electron distribution and band structure of α-Fe2O3 photoanodes to prolong the lifetime of photogenerated holes, which facilitates photogenerated carrier transport and further enhances the PEC-WS performance of α-Fe2O3 photoanode.

Utilizing samarium doped BiVO4 microspheres for solar-Powered photocatalysis and Microbial Defense

Due to their unique features and numerous uses, samarium-doped bismuth vanadate (BiVO4) photocatalysts have recently attracted a lot of interest from researchers in the area of photocatalysis. In this work, the synthesis of BiVO4 nanoparticles, both unmodified and doped with Sm3+, using a co-precipitation technique, is thoroughly examined. It is worth mentioning that the photocatalytic efficacy of Sm3+-doped BiVO4 nanoparticles was higher than that of pure BiVO4 nanoparticles. This is because the band gap was reduced and the synergistic effects of Sm3+ ions worked together to effectively suppress the recombination of photo-generated charge carriers. Improving charge carrier migration and separation, and thus photocatalytic performance is dependent on the introduction of samarium dopants. Additionally, samarium-doped bismuth vanadate was investigated for its antibacterial properties, and it was shown that it could eliminate bacteria and other germs in both watery and airborne settings using photocatalytic activity. When Sm3+ ions were added to the BiVO4 matrix, the antibacterial activity was significantly increased when tested against a variety of gram-positive and gram-negative bacteria, including, but not limited to, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Proteus vulgaris. Most importantly, the photocatalyst showed remarkable stability and recyclability; at a doping level of 7 wt% Sm3+-doped BiVO4 performed optimally. This work presents a simple method for synthesizing BiVO4 nanoparticles by co-precipitation, which shows great potential for the effective removal of organic pollutants and microbes from polluted water sources. The generated nanoparticles may be either pure or doped with Sm3+.

Improving light harvesting and charge carrier separation enabling enhanced photoelectrochemical hydrogen production by Sb2S3-decorated TiO2 nanotube arrays on porous Ti-photoanodes

The Ag + ions doped TiO2 nanotube arrays fabricated on Ti mesh through an electrochemical anodization process, and n/n heterostructure formed by coating the TiO2 nanotube array photoanode with an n-type stibnite (Sb2S3) layer improve photoelectrochemical water splitting reaction by enhancing light harvesting and charge carrier separation. Sb2S3 is chosen because of its suitable band gap position and strong visible light response. The Ag + ion incorporated TiO2 nanotube array coated with Sb2S3 exhibits a photocurrent density of 6.5 mA cm−2 vs. RHE, whereas bare TiO2 nanotube array coated with Sb2S3 and pristine TiO2 nanotube array exhibit photocurrent densities of 3.6 and 0.27 mA cm−2, respectively, under the same conditions, which is nearly 1.8 and 24 times greater than the TiO2 nanotube array coated with Sb2S3 and pristine TiO2 nanotube array photoanodes. The applied bias photon-to-current efficiency of Ag + ion incorporated TiO2 nanotube array coated with Sb2S3 is 3.6% and the improved Photoelectrochemical performance of Ag + ion doped TiO2 nanotube array coated with Sb2S3 is attributable to higher conductivity of TiO2 nanotube array caused by increased oxygen vacancies and broad optical activity of Sb2S3. The 1-dimensional TiO2 nanotube array device structure in the Ti mesh improves charge separation and light harvesting while reducing photogenerated charge carrier recombination and the potential of this novel device structure for advanced energy conversion applications is highlighted in this study.

Developing Z-scheme Bi2MoO6@α-MnO2 beaded core-shell heterostructure in photoelectrocatalytic treatment of organic wastewater

Photoelectrocatalysis (PEC) oxidation technology with the combination of electrocatalysis and photocatalysis is an ideal candidate for treatment of dyeing wastewater containing multifarious intractable organic compounds with high chroma. Constructing high-quality heterojunction photoelectrodes can effectively suppress the recombination of photo-generated carriers, thereby achieving efficient removal of pollution. Herein, a beaded Bi2MoO6@α-MnO2 core-shell architecture with tunable hetero-interface was prepared by simple hydrothermal-solvothermal process. The as-synthesized Bi2MoO6@α-MnO2 had larger electrochemically active surface area, smaller charge transfer resistance and negative flat band potential, and higher separation efficiency of e−/h+ pairs than pure α-MnO2 or Bi2MoO6. It is noteworthy that the as-synthesized Bi2MoO6@α-MnO2 showed Z-scheme heterostructure as demonstrated by the free radical quenching experiments. The optimized Bi2MoO6@α-MnO2-2.5 exhibited the highest degradation rate of 88.64% in 120 min for reactive brilliant blue (KN-R) and accelerated stability with long-term(∼10000s) at the current density of 50 mA cm−2 in 1.0 mol L−1 H2SO4 solution. This study provides valuable insights into the straightforward preparation of heterogeneous electrodes, offering a promising approach for the treatment of wastewater in various industrial applications.

Inducing Cu2+ species to SrTiO3 nanofibers based on blend electrospinning for boosting CO2 photoreduction to CH3OH

Photocatalytic CO2 reduction presents a promising strategy to alleviate environmental issues caused by massive CO2 emissions. SrTiO3, a potential photocatalyst for photocatalytic CO2 reactions, is limited by poor photoresponsivity and fast photogenerated carrier recombination. In this work, a series of Cu2+ species modified SrTiO3 nanofibers (xCuO/STO) was prepared combining sol-gel method and electrospinning with different copper content. The CH3OH yield of the 0.08CuO/STO photocatalyst reached up to 5.75 ± 0.27 μmol g−1 h−1, which was 2.2 times higher than that of pure SrTiO3. It was attributed that the blend electrospinning promoted Cu2+ species to be well dispersed on the surface of the SrTiO3 nanofibers. The strategy effectively enhanced the light absorption of the photocatalyst and inhibited the recombination of the photogenerated carriers. Part of appropriate characterizations were employed to elucidate the above point. In addition, to explore the inherent mechanism between the two species, the Density Functional Theory (DFT) calculations were further applied in the inherent mechanism between the species. This work provided a blend electrospinning approach for designing cocatalyst-modified SrTiO3 nanofibers for photocatalytic reduction of CO2.