Effective Carrier Separation Research Articles

Enhanced photocatalytic hydrogen evolution by S-scheme heterojunction and metal phosphide in NiTiO3/Graphdiyne

A key strategy to improve photocatalytic reaction efficiency is to achieve effective separation and migration of photo-generated carriers. Heterojunctions and co-catalysts are essential for boosting charge separation and transfer, reducing activation energy, and providing active sites for surface redox reactions. Herein, we introduce a composite catalytic system based on NiTiO3, enhanced with Graphdiyne (GDY) and NiP, achieving a hydrogen production activity of 8.37 mmol g−1 h−1. This performance is attributed to the combined effects of S-scheme heterojunction formation and NiP nanoparticle generation through phosphorylation. The S-scheme heterojunction effectively separates electron-hole pairs, reducing charge transport distance. Additionally, NiP nanoparticles formed in situ promote faster charge separation from NiTiO3 and act as active sites to accelerate the reduction half-reaction. Consequently, NiTiO3/GDY-P exhibits higher light absorption, faster charge separation, and superior redox capacity compared to NiTiO3. This work presents an efficient, eco-friendly multiphase catalytic system based on an S-scheme heterojunction and metal phosphide.

Photodynamic antibacterial activity of CoTiO3/ZnIn2S4 Z-type heterojunction and its efficient enhancement mechanism by reactive oxygen species

The Solar-powered photocatalytic antibacterial technology has received widespread attention as a safe and efficient environmental self-cleaning technology, but its application remains a challenging task. Taking inspiration from the design of heterojunction structures in photocatalytic materials, this study employed a precipitation in-situ synthesis method to successfully construct a CoTiO3/ZnIn2S4 (CTZIS) Z-scheme heterojunction with excellent photocatalytic performance by depositing layered ZnIn2S4 nanosheets in situ on a rod-shaped CoTiO3 support. After visible-light irradiation for 20 min, the CTZIS antimicrobial agent (100 μg/mL) exhibited an ultra-high bacterial inactivation rate of 99.9 %, which was 10 and 11 times higher than that of ZnIn2S4 and CoTiO3 under the same conditions, using E. coli as the study object. Meanwhile, bacteria treated with CTZIS exhibited the highest degree of cell membrane lipid peroxidation and the lowest activity of intracellular respiratory chain dehydrogenase, demonstrating excellent antibacterial performance. After testing and calculation, it was found that the excellent antibacterial activity comes from the solid gap electric field between heterojunctions, which enhances the effective spatial separation of photo-generated carriers and effectively increases the quantum yield of reactive oxygen species (ROS). The synergistic antibacterial mechanism of CTZIS from bacterial surface to bacterial interior co-damage was revealed, in which the production of • O2‐ and •OH are a key active substance in the process of bacterial oxidative stress inactivation.

Modulating Schottky barriers and active sites of Ag-Ni bi-metallic cluster on mesoporous carbon nitride for enhanced photocatalytic hydrogen evolution

The advancement of photocatalysis relies on the development of novel hetero-structured materials with unique architectures. In this study, we successfully synthesized a hetero-structured g-C3N4 (GCN) material with a distinctive surface-interface modification. To further enhance its photocatalytic performance, we optimized the Ag and Ni concentration to maximize the visible light absorption and catalytic active sites for hydrogen evolution reactions. By using systematic physicochemical characterizations and density functional theory (DFT) calculations, we elucidated the pivotal role of graphitic carbon nitride (g-C3N4) in facilitating the formation of an efficient charge transfer channel and promoting the effective generation and separation of photo-generated carriers. From the DFT calculations, we also demonstrated that the Ag and Ni nanoparticles provide more efficient visible light absorption and active sites than Ni nanoparticles for water splitting and hydrogen evolution and In-situ TEM exploration. Furthermore, the hetero microstructure consisting of thin g-C3N4 nano scrolls has a crucial role in shortening the migration distance of the carriers, effectively suppressing carrier recombination. Consequently, these extraordinary characteristics resulted in a superior solar light-driven photocatalytic H2 evolution rate of 2507 μmol.h-1.g−1, surpassing the rate achieved by g-C3N4 heterostructures by a remarkable 18.6-folds. Moreover, the apparent quantum efficiency of this hetero-structured material reached an exceptional value of 1.6 % under a 1.5 G air mass filter.

Bi6Fe2Ti3O18 ferroelectrics with various morphologies under mild conditions by crystal growth control for promoted adsorption-piezo-photocatalytic degradation performances

Bi6Fe2Ti3O18 (BFTO) Aurivillius phase layered perovskite ferroelectric materials with spontaneous polarization and piezoelectric effect, have garnered significant attention in photocatalysis owing to their unique advantage of enhancing electron-hole separation. Herein, morphological engineering is used to improve the photocatalytic, piezo-catalytic, and piezo-photocatalytic activities of BFTO, and BFTO nanocrystallites with diverse morphologies such as nanosheet, nanoparticle, nanosheets-assembled flower-like structures were successfully synthesized using a hydrothermal method under mild conditions. Among these structures, the flower-like BFTO sample exhibits efficient absorption of visible light, excellent adsorption performance, enhanced piezoelectric response, and effective carrier separation, thereby contributing to its superior adsorption-photocatalytic, adsorption-piezo-catalytic, and adsorption-piezo-photocatalytic activities for Rhodamine B. Furthermore, corona poling was further applied to enhance the macroscopic polarization and piezoelectric response of the BFTO photocatalyst, thereby leading to more effective separation of photogenerated carriers in the polarized samples. The polarized BFTO microflowers exhibit excellent photocatalytic, piezo-catalytic, and piezo-photocatalytic activities with reaction rate constants of 0.222 min−1, 0.168 min−1, and 0.255 min−1. Based on the results of piezoresponse force microscopy and finite element simulation, the greater piezoelectric response was confirmed in the polarized flower-like BFTO compared to the other samples. Overall, the synergistic effect of morphology control and polarization engineering is effective for achieving Bi-based Aurivillius phase layered perovskite photocatalyst with excellent adsorption-photocatalytic and adsorption-piezo-photocatalytic performances.

Construction of S-scheme heterojunction via Cu2ZnSnS4 coupled with g-C3N4 for enhancing HER performance

It is shown that replacing non-noble metals with noble metals in photocatalytic water splitting is pivotal for increased and sustained hydrogen production. However, the challenge persists in designing and developing a cost-effective, highly active catalyst with effective carrier separation and providing sufficient H+ reduction sites to enhance photocatalytic H2 evolution efficiency. Herein, a series of S-scheme Cu2ZnSnS4/g-C3N4 (CZTS/CN) heterojunction composites were prepared via the hydrothermal method, followed by comprehensive characterizations for in-depth investigation. The TEM image exhibits a clear interface, showing the heterojunction formation between CZTS and CN nanosheets. The results show that incorporating CZTS cocatalyst significantly improves CN photocatalytic hydrogen evolution reaction (HER) and its performance is notably influenced by CZTS to CN mass ratio. Among CZTS/CN heterojunction composites, the 5% CZTS/CN heterojunction composite exhibited a significantly improved HER of 243.64 μmol g−1h−1, which is 29.4 and 7.08 folds superior as compared to CN (8.29 μmol g−1h−1) and CZTS (34.42 μmol g−1h−1), respectively. The mechanism study revealed that the excellent superior H2 evolution performance resulted from the established internal electric field (IEF) in p-n heterojunction, which expedites the efficient separation and migration of photoinduced carriers coupled with the distinctive flower-like configuration of CZTS offering a substantial surface area and enough active reduction sites for photocatalysis process. This work presents a rational design and an inexpensive and efficient heterojunction photocatalysis system suitable for diverse applications.

Precisely Regulating Asymmetric Charge Distribution by Single-Atom Central Doped Ag-Based Series Clusters for Enhanced Photoreduction of CO2 to Alcohol Fuels.

High efficiently photocatalytic CO2 reduction (CO2RR) into liquid fuels in pure water system remains challenged. Iron polyphthalocyanine (FePPc) with strong light harvesting, unique Fe-N4 structure, abundant pores, and good stability could serve as a promising catalyst for CO2 photoreduction. To further improve the catalytic efficiency, herein, symmetry-breaking Fe sites are constructed by coupling with atomically precise M1Ag24 (M=Ag, Au, Pt) series clusters. Especially, the introduction of Pt1Ag24 causes the most asymmetric charge distribution of Fe in FePPc (followed by Au1Ag24 and Ag25), leading to the favorable CO2 adsorption and activation. In addition, Pt1Ag24-FePPc exhibits the most effective photogenerated carriers transfer and separation. As a result, Pt1Ag24-FePPc shows the methanol/ethanol yield of 48.55/32.97 μmol·gcat-1·h-1 in H2O-CO2 system under visible light irradiation, ~ 1.65/1.25-fold, 1.83/1.37-fold, and 3.6/1.61-fold higher than that of Au1Ag24-FePPc, Ag25-FePPc, and FePPc, respectively. This work provides a concept for precisely construction and regulation symmetry-breaking sites of cluster-based catalysts for effective CO2 conversion.

High‐Hydrophilic NiCoFe–OH Accelerates Charge Interfacial Transfer and Enhances Photoelectrochemical Properties of α‐Fe2O3

α‐Fe2O3/NiCoFe–OH photoelectrode with high hydrophilicity is obtained by hot alkali etching on the surface of α‐Fe2O3/NiCoFe–LDH. Compared with α‐Fe2O3/NiCoFe–LDH (CO3(OH)16·4H2O), α‐Fe2O3/NiCoFe‐OH photoelectrodes with high hydrophilicity show better photocurrent performance. This improvement is attributed to the highly hydrophilic NiCoFe–OH promoting effective contact between the photoelectrode and the electrolyte, thus enhancing effective carrier separation and migration on the electrode. In these findings, an effective way is provided to improve the photoelectrochemical properties of α‐Fe2O3.

Realizing Ultrafast Response Speed for Self-Powered Photodetectors with a Molecular-Doped Lateral InSe Homojunction.

The implementation of energy-saving policies has stimulated intensive interest in exploring self-powered optoelectronic devices. The 2D p-n homojunction exhibits effective generation and separation of carriers excited by light, realizing lower power consumption and higher performance photodetectors. Here, a self-powered photodetector with high performance is fabricated based on an F4-TCNQ localized molecular-doped lateral InSe homojunction. Compared with the intrinsic InSe photodetector, the switching light ratio (Ilight/Idark) of the p-n homojunction device can be enhanced by 2.2 × 104, and the temporal response is also dramatically improved to 24/30 μs. Benefiting from the built-in electric field, due to the formation of an InSe p-n homojunction after partial doping of F4-TCNQ on InSe, the device possesses a high responsivity (R) of 93.21 mA/W, with a specific detectivity (D*) of 1.14 × 1011 Jones. These results suggest a promising approach to get a lateral InSe p-n homojunction and reveal the potential application of the device for next generation low-consumption photodetectors.

In situ construction of core-shell NiFe-LDH@ZnIn2S4 direct Z-scheme heterojunction for facilitating photocatalytic H2 evolution

The development of photocatalysts with non-noble metals and the effective separation of photoexcited carriers is a significant strategy for accelerating surface reaction kinetics and promoting water splitting to produce H2. Herein, an exquisite core-shell NiFe-LDH@ZnIn2S4 heterojunction photocatalyst was constructed by in situ decoration of ultrathin ZnIn2S4 nanosheets on the surface of the flower-like NiFe-LDH microsphere. The synthesized 3D hierarchical NiFe@ZIS-25 composite exhibits enhanced photocatalytic H2 evolution activity, reaching 9.12 mmol·h-1·g-1, which is 2.52-fold higher than pure ZnIn2S4. The significant improvement in H2 evolution performance could be attributed to the hierarchical core-shell structure of the NiFe@ZIS-25 photocatalyst, which enhanced the light capture ability. In addition, the interfacial coupling effect of ZnIn2S4 and NiFe-LDH is beneficial to the migration of carriers. More importantly, the construction of Z-scheme heterojunction efficiently promotes the fast translation of photogenerated carriers while preserving a stronger reduction potential to achieve H2 evolution. This work elucidates a rational strategy to develop efficient photocatalysts with hierarchical core-shell structures for water splitting.

In2S3 nanoparticles modify the porous Fe2V4O13 nanostructure photoanode to enhance charge separation efficiency and photoelectrochemical water splitting performance

In this study, we demonstrate for the first time a promising photoanode of Fe2V4O13/In2S3 (FVO/IS) nanoparticles (NPs) for photoelectrochemical (PEC) water splitting. Most importantly, this work presents the first application of X-ray photoelectron spectroscopy in tracking electron flow direction within FVO/IS to reveal the formation of heterojunction having the electron flow from IS to FVO. Mott-Schottky measurement confirms that the modification of IS NPs establishes the type II heterojunction between FVO and IS, favorable for the transport and separation of carriers. Spectral measurements of electrochemical impedance spectroscopy, photoluminescence and Bode diagram confirm the effective separation of carriers and the prolongation of the charge lifetime in the FVO/IS heterojunction photoanode. Moreover, the electrochemical measurements evidently demonstrate the substantial enhancement in the charge separation efficiency (ηseparation) and charge transfer efficiency (ηtransfer) of the photoanode, leading to significantly enhanced PEC water splitting capability. As a result, in contrast with the pure FVO NPs photoanode, the photocurrent density of the constructed FVO/IS NPs photoanode is increased by 27 times without bias. This study paves a new approach for boosting the PEC water splitting activity of FVO photoanodes by constructing heterostructures through modification with other semiconductors.

A flexible self-cleaning/antibacterial PVDF/T-ZnO fabric based on piezo-photocatalytic coupling effect for smart mask

A novel flexible composite fabric has been engineered by combining piezoelectric poly (vinylidene fluoride) (PVDF) and tetrapod zinc oxide (T-ZnO) nanostructures, which are integrated onto a nonwoven fabric substrate. This fabric exhibits a wide array of functionalities, notably self-cleaning and antibacterial properties, facilitated by the synergistic piezo-photocatalytic coupling effect. Through the utilization of the piezoelectric effect inherent in PVDF/T-ZnO in tandem with the photocatalytic attributes of T-ZnO nanostructures, the fabric achieves concurrent degradation of organic pollutants and antibacterial efficacy when exposed to mechanical vibration and solar irradiation. The piezo-photocatalytic coupling effect engenders an internal electric field that aids in the effective separation of photo-generated carriers (electrons and holes), thereby diminishing recombination rates and augmenting the efficiency of the photocatalytic degradation process. Notably, organic pollutants such as methylene blue and azithromycin exhibit degradation levels of 96.0% and 92.6%, respectively, within a timeframe of 25 and 60 min. The incorporation of PVDF/T-ZnO results in an approximate 40% enhancement in the degradation rate of organic substances compared to the use of T-ZnO in isolation. Furthermore, the composite fabric showcases exceptional antibacterial efficacy, effectively inhibiting the proliferation of Staphylococcus aureus. Experimental findings reveal that the average antibacterial zone diameter of the PVDF/T-ZnO fabric measures at 7.68 mm, significantly surpassing that of the T-ZnO fabric and nonwoven fabric. Given its remarkable self-cleaning and antibacterial attributes, the PVDF/T-ZnO fabric exhibits substantial potential for diverse applications, including the development of intelligent masks tailored for deployment in healthcare settings and polluted environments.

Construction of 2D/2D NH2-TiO2/ReS2 molecular-connected heterojunction to achieve selective carrier transport for photocatalytic hydrogen production

The 2D/2D heterojunction photocatalyst demonstrates a broad range of applications owing to its large interface contact area. At present, most of the current 2D/2D structures are constructed by self-assembly, which mainly forms a relatively weak van der Waals force at the interface. This poses a challenge to achieving effective carrier separation. Here, we proposed an innovative strategy of molecular-connected heterojunctions to address this challenge. The strategy uses (3-aminopropyl) trimethoxysilane (APTMS) to modify the surface of TiO2 and construct NH2-TiO2/ReS2 heterojunction, which not only alters the material’s Zeta potential but also uses molecular chains connecting TiO2 and ReS2. Simultaneously, the design of molecular-connected heterojunction changes the work function of TiO2, leading to the transformation of the TiO2/ReS2 heterojunction from type-Ⅰ to S-scheme, thereby achieving a selective carrier separation. The constructed NH2-TiO2/ReS2 photocatalytic heterojunction composite has a hydrogen production rate of 451.3 μmol g-1 h−1, which is over 11 and 3 times than TiO2 and TiO2/ReS2, respectively, and exhibits excellent long-term photocatalytic stability. This study presents a novel approach for achieving strong interface bonding and introduces an innovative approach for constructing 2D/2D photocatalytic heterojunctions.

Construction of S-scheme cyano-modified g-C3N4/TiO2 film with boosted charge transfer and highly hydrophilic surface for enhanced photocatalytic degradation of norfloxacin

Developing highly efficient and recyclable photocatalysts has been regarded as an attractive strategy to solve antibiotic contaminants. Herein, we designed and fabricated Cy-C3N4/TiO2 S-scheme heterojunction film with boosted charge transfer and a highly hydrophilic surface. The as-prepared heterojunction exhibited outstanding removal efficiency on tetracyclines and fluoroquinolone antibiotics (more than 80 % within 90 min). The removal rate of 300-Cy-C3N4/TiO2 on norfloxacin (NOR) was 2.12, and 1.59 times higher than that of pristine TiO2, C3N4/TiO2, respectively. The excellent photocatalytic performance of 300-Cy-C3N4/TiO2 was attributed to the highly hydrophilic surface and effective transfer and separation of carriers. Moreover, the NOR degradation pathways were proposed based on the results of density functional theory (DFT), and liquid chromatography-mass spectrometry. The toxicity assessment indicated the toxicity of intermediates can be remarkably alleviated. The DFT calculation and selective photo-deposition experiment demonstrated that an internal electric field was formed at the heterojunction interface, and the charge carriers migrated between Cy-C3N4 and TiO2 following an S-scheme transfer pathway. This research not only provides a promising method for tracking charge distribution on thin-film heterojunction photocatalysts but also helps us to design high-efficiency, and recyclable heterojunctions to solve antibiotic contaminants.

Construction of highly active photocatalytic interfaces through light field modulation and photo-deposition of Pd sites

Anchoring noble metal sites through photo-reduction is an effective way to modulate charge distribution on photocatalytic interfaces, thereby enhancing photocatalytic performance. The irradiation field on the exposed surfaces of photocatalysts has an important influence on the morphology and distribution of noble metal sites. However, non-uniform light field derived from the scattering effects of particle-form photocatalysts hinders the well-distributed photo-deposition of noble metal sites. To address this challenge, we proposed a photo-deposition method utilizing the optical fiber coated with photocatalysts. TiO2 nanorod (NR) array was coated on the optical fiber to achieve a well-distributed irradiation filed across the NR array. This resulted in a concentration of the irradiation field primarily within the NR array, maintaining uniformly distributed light intensities throughout. Palladium (Pd) sites dominated by nanoclusters were well distributed on TiO2 NR array utilizing a photo-reduction method. These Pd sites functioned as electron acceptors, facilitating the effective separation and transfer of photo-generated carriers. Consequently, an highly active photocatalytic reaction interface was constructed, demonstrating the accumulation of a substantial concentration of holes and their efficient conversion into hydroxyl radicals (·OH). Notably, hydroxyl radicals with a concentration of 62.6 μM could be generated within 14.4 min. The construction of this efficient photocatalytic interface offers an optimal platform for accelerating photocatalytic reactions and enhancing photocatalytic efficiency.

Preparation of Ti4O7/h‐BN self‐supported ceramic photoelectrode and its photoelectrocatalytic performance for water purification

AbstractThe construction of high‐efficiency self‐supported ceramic photoelectrode based on ideal semiconductor materials is essential for achieving effective degradation of pollutants by photoelectrocatalysis (PEC) technology. Herein, a Ti4O7/h‐BN composite ceramic photoelectrode with a unique microstructure was fabricated by a step‐by‐step calcination process and used in PEC water pollution remediation. The PEC activity of Ti4O7 ceramic photoelectrode could be enhanced by introducing hexagonal boron nitride (h‐BN) nanoparticles on the surface. The most optimized Ti4O7/h‐BN photoelectrode exhibited the decolorization rate of active brilliant blue KN‐R at about 97.79% in 30 min. The PEC activities could remain stable during five degradation cycles. The excellent photoelectrocatalytic performance of Ti4O7/h‐BN ceramic photoelectrode could be attributed to the low Tafel slope, low charge transfer resistance, large electrochemical active area, and excellent photo‐generated carrier separation efficiency. A type‐II heterojunction was formed between the Ti4O7 and h‐BN, which caused more effective carrier separation and enhanced the generation of dominant active species •O2− and h+. This work provided a mature synthesis strategy of Ti4O7/h‐BN self‐supported ceramic photoelectrodes with excellent practical application prospects to achieve superior PEC performance for water purification.

CaFe2O4/Ag/ZnO z-scheme heterojunction material for photocatalytic decomposition of ciprofloxacin

The Z-type heterojunction CaFe2O4/Ag/ZnO composite photocatalyst was successfully synthesized by the microwave-assisted hydrothermal methods. The photocatalytic activity of the CaFe2O4/Ag/ZnO was evaluated by the degradation of ciprofloxacin (CIP). The characterization results indicated that Ag doping can decrease the band gap (Eg) of ZnO and enhance its visible light absorption capacity. Ag/ZnO forms a Z-type heterojunction with CaFe2O4, which can significantly promote effective photogenerated carrier separation and enhance the visible light catalytic activity of the CaFe2O4/Ag/ZnO composite catalyst. It was observed that the degradation effect of the CaFe2O4/Ag/ZnO on CIP was significantly better than pure ZnO and CaFe2O4.

Z-scheme heterojunction photocatalyst formed by MOF-derived C-TiO2 and Bi2WO6 for enhancing degradation of oxytetracycline: Mechanistic insights and toxicity evaluation in the presence of a single active species

In the work, Bi2WO6/C-TiO2 photocatalyst was successfully synthesized for the first time by loading narrow bandgap semiconductor Bi2WO6 on MOF-derived carboxyl modified TiO2. The phase structure, morphology, photoelectric properties, surface chemical states and photocatalytic performance of the prepared photocatalysts were systematically investigated using various characterization tools. The degradation efficiency of oxytetracycline by 6BT Z-scheme heterojunction photocatalyst under visible light could reach 93.6 % within 100 min, which was related to the high light harvesting and effective separation and transfer of photo-generated carriers. Furthermore, the effects of various environmental factors in actual wastewater were further investigated, and the results showed that 6BT exhibited good adaptability, durability and resistance to interference. Unlike most works, the degradation system with a different single active species were designed and constructed based on their formation mechanism. In addition, for the first time, a positive study was conducted on the priority attack sites, intermediate products, and degradation pathways for the photocatalytic degradation of oxytetracycline by a single active species through HPLC-MS and Fukui index calculations. The toxicity changes of intermediate products produced in three different single active species oxidation systems were evaluated using toxicity assessment software tools (T.E.S.T.), Escherichia coli growth experiments, and wheat growth experiments. Among them, the intermediate products formed through O2– oxidation had the lowest toxicity and the main active sites it attacked were the 20C, 38O, 18C, 41O, and 55O atoms with high f+ values in the oxytetracycline molecular structure. This work provided the insight into the role of each active species in the degradation of antibiotics and offered new ideas for the design and synthesis of efficient and eco-friendly photocatalysts.

Recent advances of metal active sites in photocatalytic CO2 reduction.

Photocatalytic CO2 reduction captures solar energy to convert CO2 into hydrocarbon fuels, thus shifting the dependence on rapidly depleting fossil fuels. Among the various proposed photocatalysts, systems containing metal active sites (MASs) possess obvious advantages, such as effective photogenerated carrier separation, suitable adsorption and activation of intermediates, and achievable C-C coupling to generate multi-carbon (C2+) products. The present review aims to summarize the typical photocatalytic materials with MAS, highlighting the critical role of different formulations of MAS in CO2 photoreduction, especially for C2+ product generation. State-of-the-art progress in the characterization and theoretical calculations for MAS-containing photocatalysts is also emphasized. Finally, the challenges and prospects of catalytic systems involving MAS for solar-driven CO2 conversion are outlined, providing inspiration for the future design of materials for efficient photocatalytic energy conversion.

Organic Donor-Acceptor Systems for Photocatalysis.

Organic semiconductor materials are considered to be promising photocatalysts due to their excellent light absorption by chromophores, easy molecular structure tuning, and solution-processable properties. In particular, donor-acceptor (D-A) type organic photocatalytic materials synthesized by introducing D and A units intra- or intermolecularly, have made great progress in photocatalytic studies. More and more studies have demonstrated that the D-A type organic photocatalytic materials combine effective carrier separation, tunable bandgap, and sensitive optoelectronic response, and are considered to be an effective strategy for enhancing light absorption, improving exciton dissociation, and optimizing carrier transport. This review provides a thorough overview of D-A strategies aimed at optimizing the photocatalytic performance of organic semiconductors. Initially, essential methods for modifying organic photocatalytic materials, such as interface engineering, crystal engineering, and interaction modulation, are briefly discussed. Subsequently, the review delves into various organic photocatalytic materials based on intramolecular and intermolecular D-A interactions, encompassing small molecules, conjugated polymers, crystalline polymers, supramolecules, and organic heterojunctions. Meanwhile, the energy band structures, exciton dynamics, and redox-active sites of D-A type organic photocatalytic materials under different bonding modes are discussed. Finally, the review highlights the advanced applications of organic photocatalystsand outlines prospective challenges and opportunities.

Efficient charge separation and improved photoelectric properties of GaN/WS2/MoS2 heterojunction: A molecular dynamics simulations

Utilizing the stacking of two-dimensional (2D) materials to fabricate heterojunction represents an exceedingly effective approach for designing high-performance optoelectronic devices. In this paper, the GaN/WS2/MoS2 heterojunction was systematically studied using DFT calculations. The interface effect caused the effective separation of photo-excited carriers in the GaN/WS2/MoS2 heterojunction by inducing a stepwise transfer of the carriers, forming a build-in electric field. Due to the decrease in bandgap, the heterojunction exhibited enhanced light absorption ability across the entire spectral region. Especially, the carrier recombination time reached the microsecond level, greatly extending the lifetime of photo-excited carriers and effectively improving the energy conversion performance of photodetectors. Moreover, the augmentation of tensile strain enhances both the self-powering capacity and the near-infrared light detection capability of the GaN/WS2/MoS2 heterojunction. The exceptional performances exhibited by the GaN/WS2/MoS2 heterojunction make it a highly up-and-coming candidate for optoelectronics application.