Carrier Recombination Efficiency Research Articles

Effects of TMIn Flow Rate During Quantum Barrier Growth on Multi-quantum Well Material Properties and Device Performance in GaN-Based Laser Diodes

Abstract Multidimensional influence of indium composition in barrier layers on GaN-based blue laser diodes (LDs) are discussed through both material quality and device physics perspectives. LDs with higher indium content in the barriers demonstrate a notably lower threshold current and shorter lasing wavelength compared to those with lower indium content. Our experiments reveal that higher indium content in the barrier layers can partially reduce indium composition in the quantum wells, a novel discovery. Employing higher indium content barrier layers leads to improved luminescence properties of MQW region. Detailed analysis reveals that this improvement can be attributed to better homogeneity in the indium composition of the well layers along the epitaxy direction. InGaN barrier layers suppressed lattice mismatch between barrier and well layers, thus mitigating the indium content pulling effect in well layers. In supplement to experimental analysis, theoretical computations are performed, showing that InGaN barrier structures can effectively enhance carrier recombination efficiency and optical confinement of LD structure, thus improving output efficiency of GaN-based blue LDs. Combining these theoretical insights with our experimental data, we propose that higher indium content barriers effectively enhance carrier recombination efficiency and indium content homogeneity in quantum well layers, thereby improving the output performance of GaN-based blue LDs.

Terpyridine Ni(II) Complex Grafted CdS Nanorods for Cooperative Selective Benzyl Alcohol Oxidation and Hydrogen Production.

Efficient utilization of photogenerated charge carriers to realize photocatalytic solar fuel production and oxidative chemical synthesis is a challenging task. Herein, a conventional amidation reaction route is adopted to successfully construct a novel composite photocatalyst composed of a Ni(II)-terpyridine complex with carboxyl groups grafted on CdS nanorods (labeled as CdS@Ni(terpyC)2). Experimental results have unequivocally revealed that the as-fabricated composite catalyst exhibited a remarkable enhancement in photocatalytic activity for the dehydrogenation of benzyl alcohol under visible light, demonstrating superior hydrogen evolution efficiency and benzaldehyde selectivity, surpassing both pristine CdS and the blend of CdS and Ni(terpyC)2. The carrier dynamics study demonstrated that the Ni(terpyC)2 on the surface of CdS could quickly extract the photogenerated electrons of CdS, which reduced the carrier recombination efficiency, further improving the photocatalytic activity of the catalyst. This work illustrates the effect of surface active site engineering on photocatalysis and is expected to shed substantial inspiration on future surface modulation and design of semiconductor photocatalysts.

16.48% Efficient solution-processed CIGS solar cells with crystal growth and defects engineering enabled by Ag doping strategy

Solution-processed Cu(In,Ga)Se2 (CIGS) solar cells suffer from serious carrier recombination and power conversion efficiency (PCE) loss because of the poor film properties and easy formation of defects. Herein, we propose Ag&Se co-selenization strategy to enhance the crystallization and passivate harmful defects of the CIGS films. The formation of Ag-Se phase during the selenization process enables the formation of large grains and suppresses the deep level defects. It is found that Ag doping can enlarge the depletion region width, lower the Urbach energy and prolong the carrier lifetime. As a result, a champion solution-processed CIGS solar cell presents a high efficiency of 16.48% with the highly improved open-circuit voltage (VOC) of 662 mV and fill factor (FF) of 75.8%. This work provides an efficient strategy to prepare high quality solution-processed CIGS films for high-performance CIGS solar cells.

Highly efficient blue light-emitting diodes based on mixed-halide perovskites with reduced chlorine defects.

Perovskite light-emitting diodes (PeLEDs) provide excellent opportunities for low-cost, color-saturated, and large-area displays. However, the performance of blue PeLEDs lags far behind that of their green and red counterparts. Here, we show that the external quantum efficiencies (EQEs) of blue PeLEDs scale linearly with the photoluminescence quantum yields (PL QYs) of CsPb(BrxCl1-x)3 nanocrystals emitting at 460 to 480 nm. The recombination efficiency of carriers is highly sensitive to the chlorine content and the related deep-level defects in nanocrystals, causing notable EQE drops even with minor increases in chlorine defects. Minor adjustments of chlorine content through rubidium compensation on the A-site effectively suppress the formation of nonradiative defects, improving PL QYs while retaining desirable bandgaps for blue-emitting nanocrystals. Our PeLEDs with record-high efficiencies span the blue spectrum, achieving peak EQEs of 12.0% (460 nm), 16.7% (465 nm), 21.3% (470 nm), 24.3% (475 nm), and 26.4% (480 nm). This work exemplifies chlorine-defect control as a key design principle for high-efficiency blue PeLEDs.

The highly efficient photodegradation of 4-bromophenol by TiO2/g-C3N4 nano photocatalyst with LED visible light

Since traditional photocatalysts have suffered from higher charge carrier recombination and moderate photocatalytic efficiency, developing photocatalysts is crucial for water treatment objectives. Hence, the various ratios of TiO2 on g-C3N4 (CN) to form nano photocatalysts were synthesized by the solvothermal method. The 30%TiO2/CN showed the best performance to degradation and debromination of 4-bromophenol (4-BP) solution completely (kobs = 6.6 × 10−2 min−1) under visible light emitted by LED (420 nm) in 30 min. Remarkably, the photocatalyst showed superior stability and reusability, maintaining its efficiency after four cycles of 4-BP degradation. The dominant ROS participating in 4-BP degradation were ●O−2 and photogenerated holes (h+), as investigated by free radical scavenging tests. The optical properties analysis revealed that the introduction of TiO2 to the bulk CN decreases electron-hole recombination and improve photocatalytic performance by facilitating electrons transfer through the TiO2 nanoparticles in a chain. The findings of this study showed that the TiO2/CN photocatalyst is a promising catalyst for the degradation of 4-BP. It exhibits a higher rate constant and photocatalytic efficiency compared with previous studies conducted under visible light irradiation.

Construction of novel S-defects rich ZnCdS nanoparticles for synergistic visible light assisted photocatalytic degradation of rhodamine B: Insights into mechanism, pathway and by-products toxicity evaluation

The contamination of wastewater by azo dyes indicates serious environmental risks. Currently, industries worldwide use approximately 700,000 tons of these dyes annually, making their removal a significant challenge. In photocatalysis research, a prominent area of dedication to the advancement of visible light photocatalysis aims to achieve superior performance in overall activity. In this study, we fabricated ZnCdS nanoparticles (NPs) via a simple co-precipitation strategy, and sulphur (S)-defect-rich ZnCdS NPs (D-ZnCdS) were created through the ball milling method. These S-defect nanoparticle (NPs) catalysts were utilized for rhodamine B (RhB) dye photocatalytic degradation experiment. (XRD) X-ray diffractometer, X-ray photoelectron spectroscopy (XPS), surface-enhanced Raman spectroscopy, and photoluminescence (PL) spectroscopy characterization studies explained the induced S-defect rich in D-ZnCdS NPs. Further, the morphological, band gap determination, and photogenerated charge carrier recombination efficiency were studied using different analytical and spectroscopic characterization techniques. The Brunauer-emmett-teller (BET) results indicate the increased surface area of D-ZnCdS NPs thereby providing more active sites. The photocatalytic degrading efficiency of D-ZnCdS over RhB explains the complete degradation of pollutants within 260 min. This enhancement in the catalytic process is attributed to the increased absorption of photon energy from the visible light and large defect-rich active sites. Further, the involvement of hydroxyl (*OH) and superoxide radicals (O2*-) in the degradation of RhB along with the presence of sulphur defects, significantly improves the charge transfer in ZnCdS NPs. The involvement of certain factors like pH, ions, NCs catalyst and different RhB concentrations on RhB degradation was investigated. Additionally, D-ZnCdS NPs showed stable degrading capability even after six consecutive cycles of catalytic RhB degradation. The by products formed during the RhB photodegradation experiment were identified using Gas chromatography-mass spectrometer (GC-MS) analysis, and toxicity in fish, daphnia, and algae was examined using the Ecological structure-activity relationships (ECOSAR) program. From the above findings, the current research work provides a new strategy for utilizing defect-engineered D-ZnCdS NPs as a promising catalyst for various environmental remediation applications and paves a ways for manufacturing innovation.

Multifunctional Supramolecular Hydrogel Modulated Heterojunction Interface Carrier Transport Engineering Facilitates Sensitive Photoelectrochemical Immunosensing.

Highly responsive interface of semiconductor nanophotoelectrochemical materials provides a broad development prospect for the identification of low-abundance cancer marker molecules. This work innovatively proposes an efficient blank WO3/SnIn4S8 heterojunction interface formed by self-assembly on the working electrode for interface regulation and photoregulation. Different from the traditional biomolecular layered interface, a hydrogel layer containing manganese dioxide with a wide light absorption range is formed at the interface after an accurate response to external immune recognition. The formation of the hydrogel layer hinders the effective contact between the heterojunction interface and the electrolyte solution, and manganese dioxide in the hydrogel layer forms a strong competition between the light source and the substrate photoelectric material. The process effectively improves the carrier recombination efficiency at the interface, reduces the interface reaction kinetics and photoelectric conversion efficiency, and thus provides strong support for target identification. Taking advantage of the process, the resulting biosensors are being explored for sensitive detection of human epidermal growth factor receptor 2, with a limit of detection as low as 0.037 pg/mL. Also, this study contributes to the advancement of photoelectrochemical biosensing technology and opens up new avenues for the development of sensitive and accurate analytical tools in the field of bioanalysis.

Optimized 2D Bi[formula omitted]Se[formula omitted] thickness for broadband, high-performance, self-powered 2D/3D heterojunction photodetectors with multispectral imaging capability

The hybrid 2D/3D heterostructure, which synergistically combine the high surface area and superior surface properties of 2D materials with the volumetric advantages and mechanical stability of 3D materials, offer an efficient and unique platform for electronic, optoelectronic, and energy conversion applications. Although this structure offers numerous advantages, optimizing the performance of 2D/3D heterojunction devices still faces challenges such as interface control difficulty, doping uniformity, and scalability for mass production. To simplify and effectively optimize the performance of 2D/3D heterojunction devices, this study delves into the impact of the thickness of 2D Bi2Se3 films on the performance of Bi2Se3/GaN heterojunction photodetectors. In thinner Bi2Se3 films, a higher surface defect density increases carrier recombination efficiency, while in thicker films, an increase in internal defects impedes carrier transport. Our findings reveal an optimal film thickness that balances surface and internal defects, enhancing carrier dynamics and device performance. Remarkably, the Bi2Se3 (14.8 nm)/GaN heterojunction detector exhibits superior broadband response from ultraviolet to near-infrared, with a maximum responsivity of 0.07 A/W, a detectivity of 1.79 × 1012 Jones, and an on/off ratio of 1.02 × 104. Additionally, the device demonstrates prolonged stability in response and multispectral imaging capability. This research not only underscores the critical role of film thickness in modulating device performance but also provides novel theoretical and practical guidance for designing high-performance, self-powered, broadband heterojunction photodetectors, offering significant implications for scientific research and practical applications.

Magnetic recyclable visible light-driven Bi2WO6/Fe3O4/RGO for photocatalytic degradation of Microcystin-LR: Mechanism, pathway, and influencing factors

Photocatalysis was an attractive strategy that had potential to tackle the Microcystin-LR (MC-LR) contamination of aquatic ecosystems. Herein, magnetic photocatalyst Fe3O4/Bi2WO6/Reduced graphene oxide composites (Bi2WO6/Fe3O4/RGO) were employed to degrade MC-LR. The removal efficiency and kinetic constant of the optimized Bi2WO6/Fe3O4/RGO (Bi2WO6/Fe3O4-40%/RGO) was 1.8 and 2.3 times stronger than the pure Bi2WO6. The improved activity of Bi2WO6/Fe3O4-40%/RGO was corresponded to the expanded visible light adsorption ability and reduction of photogenerated carrier recombination efficiency through the integration of Bi2WO6 and Fe3O4-40%/RGO. The MC-LR removal efficiency exhibited a positive tendency to the initial density of algae cells, fulvic acid, and the concentration of MC-LR decreased. The existed anions (Cl−, CO3−2, NO3−, H2PO4−) reduced MC-LR removal efficiency of Bi2WO6/Fe3O4-40%/RGO. The Bi2WO6/Fe3O4-40%/RGO could degrade 79.3% of MC-LR at pH = 7 after 180 min reaction process. The trapping experiments and ESR tests confirmed that the h+, ∙OH, and ∙O2− played a significant role in MC-LR degradation. The LC-MS/MS result revealed the intermediates and possible degradation pathways.

Treatment of antibiotics in water by SO3H-modified Ti3C2 Mxene photocatalytic collaboration with g-C3N4

Due to inherent limitations such as high carrier recombination efficiency, limited active sites, and suboptimal utilization of visible light, graphite-like carbon nitride (g-C3N4) has constrained its widespread application in water treatment within photocatalytic systems. In addressing this issue, the present study employed acid etching and sonochemistry to fabricate a Ti3C2-SO3H/g-C3N4 (TiCSOHCN) composite photocatalyst for the removal of tetracycline hydrochloride (TC). The amalgamation of Ti3C2-SO3H (TiCSOH) with g-C3N4 engendered the establishment of a discernible Schottky barrier, facilitating an expedited electron transfer rate. Photocatalytic degradation experiments demonstrate that, compared to individual components, the TiCSOHCN composite photocatalyst exhibits significantly enhanced photocatalytic activity. The removal efficiency of TC reaches 75.42 % within 2 h, and even after five cycles of experimentation, the degradation efficiency remains close to 70 %, indicating excellent stability. The augmentation can be predominantly ascribed to the cooperative influence arising from the synergy between Ti3C2-SO3H and g-C3N4. The augmentation of visible light responsiveness in g-C3N4, achieved through its modification with TiCSOH, resulted in the mitigation of photoelectron-hole pair recombination, consequently leading to an amelioration in the photocatalytic efficacy of the TiCSOHCN composite catalyst. Intermediate species arising from the degradation of tetracycline were discerned utilizing LC-MS, and conjectures regarding plausible degradation pathways were postulated. Evaluations of the ecotoxicological impact of tetracycline and its intermediates indicated a progressive diminution in toxicity throughout the course of the photocatalytic degradation process. Furthermore, through free radical capture and EPR tests, it was confirmed that ·O2– and ·OH are the primary active species responsible for the photocatalytic degradation of TC, substantiating the proposed rational photocatalytic degradation mechanism. This research provides an innovative approach to developing high-performance and stable photocatalysts.

Bandgap engineering of carbon nitride by formic acid assisted thermal treatment for photocatalytic degradation of tetracycline hydrochloride

Carbon nitride had unique structure and electronic properties, and had wide application prospects in the field of photocatalysis. However, the rapid photogenerated carrier recombination efficiency and low photocatalytic activity limit its use. Defect construction was considered to be an effective strategy to improve the photocatalytic activity of carbon nitride. In this paper, nitrogen defective carbon nitride was prepared by formic acid assisted pyrolysis. The formic acid was used to regulate the top atoms and effectively shorten the band gap. Second, the gas released during pyrolysis contributed to the construction of porous structures. SEM, TEM, BET, XPS were used to confirm the presence of nitrogen defective sites. When it was used to photocatalyze the degradation of tetracycline, the main antibiotic pollutant in Dongting Lake, the degradation rate of 95.1 % was achieved in 60 min. Compared with conventional carbon nitride, the degradation rate constants were 0.04751 min−1 and 0.02110 min−1, respectively. Compared with CN, the degradation rate constant of FCN-5 was increased 2.2 times. The photocatalytic degradation activity was verified by photochemical experiments. •O2– and 1O2 active radicals dominate the photocatalytic degradation process. The ecological safety of Dongting Lake water samples repaired by defective carbon nitride has been confirmed, and the toxicity of antibiotics to the germination and growth of legumes has been effectively alleviated. Five cycles of the experiments ensured that the material can be reused. The above work provided reference and basis for the development and design of defective carbon nitride for water body restoration in Dongting Lake basin.

Boosting N[tbnd]N tri-bond activation and NH3 generation rate through simple surface Ag modification

NH3 photosynthesis from nitrogen remains a big challenge due to the extreme difficulty for the activation of NN bond. In this work, Ag-modified MoO3·0.55 H2O nanorods (named as Ag@Mo) are prepared by a simple photoreduction method. Under visible light (λ ≥ 420 nm) for 60 min, the NH3 yield over 2%Ag@Mo (molar ratio of Ag to MoO3·0.55 H2O) reaches 242.0 μmol·gcat−1, which is about 2.8 times higher than MoO3·0.55 H2O under the same conditions. The effect of Ag modification on photocatalytic ammonia synthesis is explored through experiments and theoretical calculations. The excellent photocatalytic performance is mainly attributed to the localized surface plasmon resonance effect of Ag and the successful construction of Mott-Schottky junction, which improves light utilization efficiency and reduces carrier recombination efficiency, respectively. Moreover, density functional theory calculations theoretically prove that over Ag@Mo, Ag provides new adsorption sites, and the NN tri-bond length is elongated by about 16.2%, confirming that Ag modification obviously promotes the activation of NN tri-bond. The ammonia generation rate is obviously higher than the previously reported results.

Photocatalytic fuel cell assisted by Fenton-like reaction for p-Chloronitrobenzen degradation and electricity production through S-scheme heterojunction C3N5 modified TNAs photoanode: Performance, DFT calculation and mechanism

Photocatalytic fuel cell (PFC) is a promising technology to recover usable energy from wastewater through the degradation of pollutants, whereas the complex preparation procedures and high photogenerated carrier recombination efficiency of photoanode remains an urgent challenge to improve the PFC performance. Herein, PFC with S-scheme heterojunction C3N5/TNAs photoanode assisted by Fenton-like reaction (C3N5/TNAs-PFC-Fenton) system was built for p-Chloronitrobenzene degradation and electricity production. The working function confirmed the band bending of C3N5 and TNAs, and density functional theory calculations indicated the formation of internal electric field at heterojunction interface of C3N5 and TNAs, which promoted visible-light absorption capacity and charge transfer property of C3N5/TNAs photoanode. The incorporation of Fenton-like reaction into C3N5/TNAs-PFC-Fenton system could effectively enhance p-Chloronitrobenzene degradation and electricity production by participating in free radical chain reaction and stimulating electron transfer. The radical trapping experiments confirmed that •OH and photogenerated electron were main reactive species, and photogenerated hole, •O2− and 1O2 were also participated in p-Chloronitrobenzene degradation. The p-Chloronitrobenzene degradation pathway was interpreted and the overall toxicity of p-Chloronitrobenzene was relieved after treatment in C3N5/TNAs-PFC-Fenton system. The C3N5/TNAs-PFC-Fenton system exhibited fine universality for degradation of organic pollutants and electricity production.

Boosting the photocatalytic activity of β-FeOOH catalyst for toluene oxidation by constructing internal electric field at 0D/1D homojunction interfaces

Photocatalytic degradation is considered as the most energy-efficient, environmentally benign, and effective method for treating low fraction organic contaminants. However, the photocatalysts still suffer from low utilization efficiency of visible-light and severe carrier recombination. Heterojunctions can resolve these two main problems in some extent but still be restrained by the low quality of hetero-interface. In this study, homojunction was constructed of β-FeOOH quantum dots and nanorods with the same lattice by a two-step precipitation method, to avoid the heterointerface with too many defects and possess good charge separation as a consequence. The catalysts were characterized by activity test, electron spin resonance, Mott-Schottky plots, photocurrent density tests and open-circuit potential measurements, etc. The results revealed that a strong internal electric fields (IEFs) was created at the interface of catalyst. Beneficently, the electron rearrangement leads to a more rational distribution of oxygen vacancies in the catalyst, resulting in more efficient dissociation of oxygen molecules and formation of active radicals, thus facilitating the efficient degradation of toluene. This study proposes a novel strategy to boosting the photocatalytic activity of low dimensional semiconductors via forming homojunction interfaces to improve their charge transfer.

Piezoelectric polarization induced by dual piezoelectric materials ZnO nanosheets/MoS2 heterostructure for enhancing photoelectrochemical water splitting

Zinc oxide (ZnO) has a broad range of applications in piezo-photoelectrochemical water splitting. However, the narrow light absorption range and high photogenerated carrier recombination efficiency make ZnO somewhat limited in applying piezo-photoelectrochemical water splitting. Heterogeneous structure construction is a superior handle to these two drawbacks. Herein, few-layer molybdenum disulfide (MoS2) nanospheres are compounded on ZnO nanosheets (NSs) to form a dual-piezoelectric-material heterojunction of ZnO NSs/MoS2. The photocurrent density of ZnO NSs/MoS2 reaches 0.68 mA/cm2 at 1.23 V vs. RHE under ultrasonic vibrations. It is 2.4 times higher than that of ZnO NSs under ultrasonic vibrations. The efficient piezo-photoelectrochemical performance is attributed to increased absorption range and polarization field. On the one hand, the narrow band gap of the few-layer MoS2 widens the light absorption range of ZnO. On the other hand, compared to pure ZnO NSs, ZnO NSs/MoS2 has an enhanced polarization field under ultrasonic vibrations due to the piezoelectric properties of dual piezoelectric materials, which dramatically accelerates the electron transfer and suppresses the recombination of between electrons and holes. This work provides a new approach to constructing photoelectrodes with effective piezoelectric photocatalytic properties.

Carbon nanotubes as electron mediators for CNTs/CdS/MoS2 high efficient photodegradation of tetracycline under visible light

The ternary nanocomposites of CNTs/CdS/MoS2 was synthesized by a simple two-step hydrothermal method and characterized accordingly. In situ growth of CdS on the surface of CNTs decreased the size of CdS particles and increased its dispersibility. Moreover, CdS took advantage of the good conductivity of CNTs to accelerate the conduction of photogenerated holes and reduced the recombination efficiency of charge carriers. MoS2 grew in situ on the surface of CdS, and the interface between them formed a close contact heterostructure. The built-in electric field formed at the interface between the two forced the photogenerated electrons of CdS and the holes of MoS2 to recombine here. This property not only changed the path of photogenerated electrons and holes, but also made the surface of MoS2 becoming the active center of reduction reaction. The hybrid structure of CNTs/CdS/MoS2 in-situ composite significantly improved the photocatalytic performance. When CNTs/CdS/MoS2 was used as photocatalyst, the degradation rate of tetracycline was 96.7% under 100 min of visible irradiation, and the data was still above 95% after 5 cycles indicate. This indicated that the ternary complex has good photocatalytic performance and stability. The successful preparation of CNTs/CdS/MoS2 provides an economically feasible approach for the degradation of tetracycline.

Photoelectrocatalytic degradation of tetracycline through C3N5/TiO2 nanotube arrays photoanode under visible light: Performance, DFT calculation and mechanism

TiO2 nanotube arrays (TNAs) has been widely applied as a photoanode to improve the chemical stability of electrodes in the photoelectrocatalytic (PEC) system, whereas the practical application of TNAs in organic pollutant degradation is restricted due to low visible-light response and high recombination efficiency of photoinduced carriers. In the present work, the nitrogen-rich carbon nitride (C3N5) modified TNAs (C3N5/TNAs) photoanode was constructed for tetracycline (TC) degradation in the PEC system under visible light. The introduction of C3N5 promoted the photoconversion efficiency and improved the photocatalytic performance by reducing the recombination efficiency of photoinduced carriers. The radical capture experiments verified that •OH and holes were the predominant reactive species, while 1O2, •O2- and electron participated in TC degradation in the PEC system. The density functional theory calculations and HPLC-MS spectra revealed the possible degradation pathway of TC. The toxicity estimation indicated that the overall toxicities of TC were diminished after degradation in PEC system.

Mn doping enhances the photocatalytic performance of Bi2Fe4O9 photocatalyst

Bi2Fe4(1-x)Mn4xO9 photocatalyst was prepared by the coprecipitation-hydrothermal method. After doping Mn2+, the photogenerated carrier recombination efficiency of Bi2Fe4O9 was reduced, the electron transfer efficiency was accelerated, and had a good degradation effect for RhB. When Mn2+ doping was 6%, the degradation effect of organic dyes was very good, reaching 82.29%, and the reaction rate constant was 0.00665min−1, which was 2.5 times that of Bi2Fe4O9. The main active component of the dye degradation process was ·OH, which was consistent with that of Bi2Fe4O9.

Interfacial chemical bond-modulated Z-scheme Cs2AgBiBr6/WO3 enables stable and highly efficient photocatalysis

Lead-free double perovskite Cs2AgBiBr6 has been widely devoted to photocatalysis owing to its outstanding optical properties. However, insufficient redox capacity and high photogenerated carrier recombination efficiency of Cs2AgBiBr6 would limit its effective performance. Herein, we have developed Cs2AgBiBr6/WO3 Z-scheme heterojunction for enabling stable and highly efficient photocatalysis by building interfacial chemical bonds at the interface. The internal electronic structure of Z-scheme heterojuction by regulating close coupling interfacial chemical bonds at the hetero-interface could accelerate the charge transfer, enhance the separation efficiency of photogenerated carriers and maximize the redox ability. The Cs2AgBiBr6/WO3 exhibits superior photocatalytic degradation, which could degrade 93.64% and 100% (complete mineralization) of Methyl Orange and Rhodamine B within 30 min and 25 min, respectively. The effective degradation of pollutants is ascribed to the electron-transfer mechanism of Z-scheme with reducing recombination rate of the photogenerated carriers, which could produce dominant O2– and supporting OH to effectively degrade the pollutants.

The coupling effect of functional bipartite hetero-interfaces accelerated TiO2-based photocatalysis

TiO2 is a promising environmental remediation photocatalyst that mitigates environmental damage and addresses energy needs by improving the removal efficiency of pollutants from mixed wastewater. To break the technical bottleneck of low visible light utilization and high carrier recombination efficiency of traditional TiO2, a photocatalyst MMT@Cu2+-Fe3O4/TiO2 (M-Cu/FT) with functional bipartite hetero-interfaces was prepared via a two-step water bath reflux method. Ordered self-assembly Cu2+-Fe3O4/TiO2 hetero-interfaces are growing along the edge of MMT with positive potential. MMT@Cu2+-Fe3O4 hetero-interfaces and Cu2+-Fe3O4/TiO2 hetero-interfaces are regarded as independent workstations for electron enrichment and hole retention, respectively, which are equipped with Al-O-Fe(Cu2+) and (Cu2+)Fe-O-Ti bonds that can be served as carrier transport channels to construct intelligently tunable oxidation/reduction systems. The Cu2+ doping not only induces the generation of a built-in electric field by causing lattice distortion to accelerate carrier separation but also constructs traps in the valence band at the hetero-interfaces to facilitate hole trapping. It is demonstrated that M-Cu/FT is beneficial for Rh-B degradation and Cr(VI) reduction in the aqueous phase under visible irradiation, whereas the treatment efficiency of mixed wastewater can reach up to 97%, which is an appealing tendency for high-value utilization of green energy.