Field Of Photocatalysis Research Articles

Hole transfer promotion on La-MOF@MXene by valence band structure regulation for the efficient photocatalytic degradation

La-MOF has excellent thermal and chemical stability. Therefore, it can be used in the field of photocatalysis. However, the sluggish hole transfer, which is caused by low valence band position hinders its application prospects in photocatalysis, especially in hole-driven processes. In this work, we have proposed a strategy to adjust the VB structure on La-MOF, by modifying the two-dimensional (2D) conductor MXene electron-withdrawing. XRD, Raman, and HRTEM analysis indicated that the three-dimensional La-MOF was uniformly encased by the 2D MXene, and the distinct interface substantiated the successful construction of the Schottky heterojunction. XPS and UPS characterization revealed that the electron transfer from La-MOF to MXene induces an upward shift in the valence band of La-MOF to promote hole transfer. As a result, the optimized La-MOF@MXene achieved a photocatalytic degradation constant of 0.00773 min−1 for tetracycline hydrochloride within 120 min, which is 5.3 and 20 times higher than that of pure La-MOF and MXene, respectively, outperforming most previously reported works. This work can expand the application of La-MOF materials in the field of photocatalysis, providing a fresh avenue to regulate the slow hole transport.

Preparation and degradation efficiency of CeO2 and CdS composite photocatalysts

Cerium dioxide (CeO2) is an extremely versatile rare-earth oxide, which is chemically stable, nontoxic, and simple to prepare, making it of great interest in the field of photocatalysis. However, cerium dioxide has a low forbidden band width, its utilization of sunlight is not high, and the However, cerium dioxide has a low forbidden band width, its utilization of sunlight is not high, and the photogenerated carriers are very easy to compound. These problems lead to the low photocatalytic efficiency of cerium dioxide, which greatly limits the practical application of cerium dioxide photogeneration. These problems lead to the low photocatalytic efficiency of cerium dioxide, which greatly limits the practical application of cerium dioxide photocatalysts. morphologies was prepared by hydrothermal method using cerium nitrate as raw material, and then compounded with CdS to form a composite photocatalyst. The effect of morphology on the degradation efficiency of CeO2 and the change of the degradation efficiency of CeO2 with different morphologies after The effect of morphology on the degradation efficiency of CeO2 and the change of the degradation efficiency of CeO2 with different morphologies after compounding with CdS were investigated.

First Principle Study on the Z-Type Characteristic Modulation of GaN/g-C3N4 Heterojunction.

This study investigates the stability, electronic structure, and optical properties of the GaN/g-C3N4 heterojunction using the plane wave super-soft pseudopotential method based on first principles. Additionally, an external electric field is employed to modulate the band structure and optical properties of GaN/g-C3N4. The computational results demonstrate that this heterojunction possesses a direct band gap and is classified as type II heterojunction, where the intrinsic electric field formed at the interface effectively suppresses carrier recombination. When the external electric field intensity (E) falls below -0.1 V/Å and includes -0.1 V/Å, or exceeds 0.2 V/Å, the heterojunction undergoes a transition from a type II structure to the superior Z-scheme, leading to a significant enhancement in the rate of separation of photogenerated carriers and an augmentation in its redox capability. Furthermore, the introduction of a positive electric field induces a redshift in the absorption spectrum, effectively broadening the light absorption range of the heterojunction. The aforementioned findings demonstrate that the optical properties of GaN/g-C3N4 can be precisely tuned by applying an external electric field, thereby facilitating its highly efficient utilization in the field of photocatalysis.

Structural Design on Porous Aromatic Frameworks for Photocatalysis

Photocatalytic technology has shown great potential in various fields such as environmental purification, energy conversion, and chemical transformations due to its green, sustainable, and low‐cost characteristics. Porous aromatic frameworks (PAFs) with high specific surface areas, designable local structures, and abundant active sites could potentially serve as efficient photocatalysts for various catalytic reactions. This makes PAFs have a wide range of application prospects and significant advantages in the field of photocatalysis. This concept discusses the recent progress of photocatalysis over PAFs. Various strategies are used to solve the general problems of photocatalyst, such as poor light absorption, low carrier separation efficiency and poor stability, which further reveal the relationship between their structure and performance.

The application of semiconductor nanomaterials in renewable energy

Abstract. In the development of renewable energy, the usage of solar cells, fuel cells, hydrogen energy, thermoelectric energy, and thermal energy has become a significant focus of research and development. Semiconductor nanomaterials play important roles in these fields. This paper focuses on the usage of TiO2 and In2O3 in renewable energy and finds out the trends and outlook of semiconductor nanomaterials in this field. TiO2 nanomaterials have attracted widespread attention due to their unique structure and excellent properties, such as their large specific surface area, high surface activity, and sensitivity. TiO2 nanomaterials are highly active in photovoltaic applications and play an important role in the search for renewable, clean energy technologies. In2O3 is an excellent n-type transparent semiconductor functional material, characterized by high sensitivity, low resistivity, good conductivity, high catalytic activity, and wide bandgap width. It has shown good competitiveness in gas sensors, solar cells, and photocatalysis fields. Although these semiconductor nanomaterials have many advantages, there are still some drawbacks that hinder their development. There is still much work to be done for the wider application of semiconductor nanomaterials in the field of renewable energy.

DFT-Based Mechanistic Exploration and Application in Photocatalytic Heterojunctions.

Density functional theory (DFT) is one of the most widely used methods in the field of computational materials and has become an important research method for photocatalytic heterojunctions. Based on the research progress of DFT in the field of photocatalytic heterojunctions, this review introduces three kinds of heterojunction modeling in detail as well as the problems encountered in the construction process and the solutions. It provides a comprehensive review of the calculation methods of important parameters related to photocatalytic heterojunctions. Comparison, analysis, and discussion were conducted on some functional selections and calculation results based on experimental data. Finally, the limitations and shortcomings of DFT in the field of photocatalytic heterojunctions are pointed out. This review will provide valuable guidance for the calculation and analysis of the performance of photocatalytic heterojunctions and help promote the wider application of DFT in the field of photocatalysis.

Theoretical design of Z-scheme photocatalyst for water splitting with excellent catalytic performance: GeSe/PtS2 heterojunction

In the face of the urgent need for energy transition, Z-scheme heterojunctions are considered highly suitable candidates for future photocatalytic applications, owing to their exceptional optoelectronic characteristics and high catalytic efficiency. This paper systematically investigates the geometric structure, optoelectronic properties, and catalytic efficiency of the GeSe/PtS2 heterojunction through detailed first-principles calculations. The findings indicate that the band structure of the GeSe/PtS2 heterojunction presents a staggered Type-Ⅱ band alignment and exhibits an indirect band gap measuring 1.75 eV Charge transfer analysis reveals that under the interplay of an intrinsic electric field directed from GeSe to PtS2 and the band bending occurring at the heterojunction interface, the GeSe/PtS2 heterojunction conforms to the obvious Z-scheme electron transfer mechanism characteristics. This facilitates the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) to proceed smoothly on opposite sides of the heterojunction. Across the pH range of 0 to 14, the heterojunction's band edge positions successfully span the redox potentials of water, and can still meet the hydrolysis potential requirements under strain. In addition, the GeSe/PtS2 heterojunction not only effectively compensates for the poor absorption of PtS2 monolayer to visible light, but also achieves a wider visible light absorption range through the strain-induced redshift in the spectrum. At the same time, the solar to hydrogen (STH) efficiency of up to 15.56 % further underscores the substantial catalytic potential of the GeSe/PtS2 heterojunction, offering promising design strategies for a technological revolution in the field of photocatalysis.

One-step fabrication of Bi2MoO6 nanowires-g-C3N4 composites for outstanding photocatalytic performance in cyclohexane oxidation

Selective oxidation of cyclohexane into cyclohexanone (K) and cyclohexanol (A) stands as a pivotal process in industrial chemistry. However, the challenges associated with activating the C-H bond and the vulnerability of KA oil to over-oxidation detract from the economic significance of this reaction. This study focuses on the preparation of a bismuth molybdate ultrathin nanowires-carbon nitride (Bi2MoO6-g-C3N4) heterojunction through a one-step hydrothermal approach for significantly improving the photocatalytic oxidation of cyclohexane. Bi2MoO6 ultrafine nanowires with the diameter of 6 nm were adhered tightly on the surface of g-C3N4 nanosheets with the assistance of oleyl amine. The type II heterojunction of Bi2MoO6-g-C3N4 composite facilitated a more efficient separation of charges and boosted the photocatalytic performance in the cyclohexane oxidation. The Bi2MoO6-g-C3N4 composite demonstrated outstanding photocatalytic performance with a 10.66 % conversion rate of cyclohexane, surpassing the individual efficiencies of Bi2MoO6 and g-C3N4 by 1.9 and 2.2 times, respectively. Moreover, it demonstrated an outstanding KA oil selectivity of 99.32 %, showcasing exceptional levels of both conversion and selectivity simultaneously. Through the utilization of photoelectrochemical analysis, research on band structures, experiments on radical trapping and monitoring, we have extensively investigated the mechanism of photocatalysis. The type II charge transfer in Bi2MoO6-g-C3N4 heterojunction restricted the redox capacity of electrons in the conduction band and holes in the valence band, effectively curbing over-oxidation reactions of KA oil, thus achieving remarkable KA oil selectivity. It offers a valuable insight into the creation of heterojunctions to boost the efficiency of photocatalytic oxidation of cyclohexane, showing promise for advancing the field of photocatalysis.

Engineering of Graphitic Carbon Nitride (g-C3N4) Based Photocatalysts for Atmospheric Protection: Modification Strategies, Recent Progress, and Application Challenges.

Graphitic carbon nitride (g-C3N4) is a prominent photocatalyst that has attracted substantial interest in the field of photocatalytic environmental remediation due to the low cost of fabrication, robust chemical structure, adaptable and tunable energy bandgaps, superior photoelectrochemical properties, cost-effective feedstocks, and distinctive framework. Nonetheless, the practical application of bulk g-C3N4 in the photocatalysis field is limited by the fast recombination of photogenerated e--h+ pairs, insufficient surface-active sites, and restricted redox capacity. Consequently, a great deal of research has been devoted to solving these scientific challenges for large-scale applications. This review concisely presents the latest advancements in g-C3N4-based photocatalyst modification strategies, and offers a comprehensive analysis of the benefits and preparation techniques for each strategy. It aims to articulate the complex relationship between theory, microstructure, and activities of g-C3N4-based photocatalysts for atmospheric protection. Finally, both the challenges and opportunities for the development of g-C3N4-based photocatalysts are highlighted. It is highly believed that this special review will provide new insight into the synthesis, modification, and broadening of g-C3N4-based photocatalysts for atmospheric protection.

Ultra-Long Carrier Lifetime of Spiral Perovskite Nanowires Realized through Cooperative Strategy of Selective Etching and Passivation.

Spiral inorganic perovskite nanowires (NWs) possess unique morphologies and properties that allow them highly attractive for applications in optoelectronic and catalytic fields. In popular solution-based synthesis methodology, however, challenges persist in simultaneously achieving precise and facile control over morphological twisting and fantastic carrier lifetimes. Here, a cooperative strategy of concurrently employing selective etching and ligand engineering is applied to facilitate the formation of spiral CsPbBr3 perovskite NWs with an ultralong carrier lifetime of ≈2 µs. Specifically, a novel amine of 1-(p-tolyl)ethanamine is introduced to functionalize as both a selective etchant and the source of forming an effective ligand to passivate the exposed facets, favoring the structural twisting and the enhancement of carrier lifetimes. The twisting behaviors are dependent on the etch ratios, which are essentially associated with the densities of grain boundaries and dislocations in the NWs. The ultralong carrier lifetime and long-term stability of the spiral NWs open up new possibilities for all-inorganic perovskites in optoelectronic and photocatalytic fields, while the cooperative synthesis strategy paves the way for exploring complex spiral structures with tunable morphology and functionality.

Graphitic Carbon Nitride Based Semiconductors and Their Applications in the Field of Photocatalysis

An increasing number of advanced semiconductor materials have been reported with the progress of theoretical and practical researches. The graphitic carbon nitride (g-C3N4) stands out as a highly promising semiconductor photocatalyst. It is known for its visible-light reaction and good chemical stability, indicating its potential for extensive use in photocatalysis. Recently, rapid progress has been made in researching g-C3N4-based semiconductor substances in photocatalysis. Till now, a large amount of work has focused on the applications of g-C3N4 in photocatalysis. This work focuses on those researches concerning with g-C3N4-based photocatalytic substances. Their structural characteristics, synthesis techniques, and efficiency enhancement are discussed in detail. Besides, their applications in different photocatalytic reactions are also highlighted. These reactions include hydrogen production by water decomposition, degradation of organic matter, carbon dioxide reduction, and photocatalytic bactericide. This article also points out the problems and challenges in the photocatalytic performance. Meanwhile, the stability of g-C3N4 is also highlighted. It also puts forward the promising research directions of g-C3N4 in the field of photocatalysis.

A novel bi-level optimal strategy-assisted design boosting discovery of specific surface area of perovskite oxide for effective photocatalysis

Due to the inherent property of materials, photocatalysis plays a crucial role in diverse applications, such as the degradation of organic pollutants, fuel production, and nitrogen fixation. Perovskites, in particular, are remarkable for their high light absorption rate and energy conversion efficiency within the visible light range, thereby positioning them as promising photocatalysts. Given that specific surface area (SSA) is a critical metric for evaluating photocatalytic performance, accurately and quickly predicting the SSA of perovskites has emerged as a key area of technical research. Therefore, it is essential to explore the relationship between potential materials descriptors and SSA, which can significantly expedite the discovery of photocatalyzed perovskite materials with high SSA. In this study, we proposed a bi-level optimization method that combines descriptors identified strategy and model optimization strategy for predicting the SSA of unknown perovskite candidates, thereby elucidating the relationship between material features and SSA. Initially, at the upper level, the Gradient Boosting Regression combined with Recursive Feature Elimination (RFE-GBR) method was employed to identify crucial features that are closely correlated with the SSA of photocatalyzed perovskites. Subsequently, the Sure Independence Screening.Sparsifying Operator (SISSO) was utilized to develop new descriptors that exhibited strong correlations with SSA. Based on refined descriptors identifiied at the upper level, at the lower level, the optimal model strategy was obtained by Improved Osprey Optimization Algorithm (IOOA) using golden sine strategy and Gradient Boosting Regression (GBR) regression to tune the key parameters of GBR for optimizing SSA. The optimal designing method achieved remarkable predictive performance with R2 (R-squared) score of 0.90 and MAE (Mean Absolute Error) of 3.97 m2/g, along with 5-fold cross-validation. Then this method was applied to predict the SSA of 300 unidentified ABO3 perovskites. Comparison with experimental data revealed that our approach significantly accelerated the development of perovskite materials with superior photocatalytic properties, showing the potential of our model in advancing the field of photocatalysis.

Photocarrier behavior and photocatalytic H2O2 synthesis performance of amorphous/crystalline SrTiO3/BiVO4 layered heterostructures

BiVO4 (BVO), as a visible light responsive semiconductor material, has been widely employed in the field of photocatalysis. However, monoclinic BVO is afflicted by a high recombination rate of photogenerated charge carriers and poor charge transport capability, resulting in low charge utilization efficiency. Constructing heterostructures for interface modification of BVO is an effective strategy to improve photocatalytic performance. Herein, amorphous/crystalline SrTiO3/BiVO4 (STO/BVO) layered film nanoheterostructures have been successfully fabricated on the (001) yttrium stabilized zirconia substrate by magnetron sputtering. Under 440 nm monochromatic light irradiation, the H2O2 production rate of the composite film is increased by 1.2 times compared to pure BVO. The type II heterostructure composed of STO and BVO accomplishes selective interface hole transport from BVO to STO, promoting the separation of space charges. Additionally, the interaction between amorphous/crystalline interfaces effectively suppresses the photocorrosion of BVO and strengthens the stability of the film, which is of great significance for studying charge transport behavior and photocatalytic mechanisms.

Role of Morphology on Zinc Oxide Nanostructures for Efficient Photoelectrochemical Activity and Hydrogen Production.

Energy generation today heavily relies on the field of photocatalysis, with many conventional energy generation strategies now superseded by the conversion of solar energy into chemical or thermal energy for a variety of energy-related applications. Global warming has pointed to the urgent necessity of moving away from non-renewable energy sources, with a resulting emphasis on creating the best photocatalysts for effective solar conversion by investigating a variety of material systems and material combinations. The present study explores the influence of morphological changes on the photoelectrochemical activity of zinc oxide nanostructures by exploiting electrodeposition and capping agents to control the growth rates of different ZnO facets and obtain well-defined nanostructures and orientations. A zinc nitrate (Zn (NO3)2) bath was used to electrodeposit ZnO nanostructures on an indium tin oxide glass (ITO) substrate at 70 °C with an applied potential of -1.0 V. Ethylenediamine (EDA) or ammonium fluoride (NH4F) were added as capping agents to the zinc nitrate bath. Extensive evaluation and characterization of the photoelectrochemical (PEC) capabilities of the resulting morphology-controlled zinc oxide nanostructures confirmed that altering the ZnO morphology can have positive impacts on PEC properties.

Highly active Cu2O/CoCo-PBA S-scheme heterojunction for enhanced visible-light-driven hydrogen evolution

Prussian blue analogues is a unique class of organic-inorganic hybrid materials that have garnered significant attention in the field of photocatalysis due to their large specific surface area and abundant active sites. However, their potential is limited by the challenge of photogenerated charge carrier recombination. To address this issue, we successfully synthesized a tightly coupled Cu2O/CoCo-PBA S-scheme heterojunction catalyst using ultrasound-assisted and thermal treatment methods, aiming to reduce the recombination of photogenerated charge carriers. In this system, CoCo-PBA serves as the electron donor, while Cu2O acts as the electron acceptor. The closely coupled interface between these materials shortens the electron transfer distance. Under 10 W white light irradiation, the Cu2O/CoCo-PBA composite photocatalyst demonstrated remarkable hydrogen evolution activity, with a hydrogen production rate of 5.98 mmol⋅g⁻¹⋅h⁻¹, which is 6.4 times that of CoCo-PBA alone. This S-scheme heterojunction strategy lays the groundwork for the design and large-scale application of highly active visible-light-driven photocatalysts.

Preparation and Photocatalytic Performance of In2O3/Bi2WO6 Type II Heterojunction Composite Materials.

Bismuth-based photocatalytic materials have been widely used in the field of photocatalysis in recent years due to their unique layered structure. However, single bismuth-based photocatalytic materials are greatly limited in their photocatalytic performance due to their poor response to visible light and easy recombination of photogenerated charges. At present, constructing semiconductor heterojunctions is an effective modification method that improves quantum efficiency by promoting the separation of photogenerated electrons and holes. In this study, the successful preparation of an In2O3/Bi2WO6 (In2O3/BWO) II-type semiconductor heterojunction composite material was achieved. XRD characterization was performed to conduct a phase analysis of the samples, SEM and TEM characterization for a morphology analysis of the samples, and DRS and XPS testing for optical property and elemental valence state analyses of the samples. In the II-type semiconductor junction system, photogenerated electrons (e-) on the In2O3 conduction band (CB) migrate to the BWO CB, while holes (h+) on the BWO valence band (VB) transfer to the In2O3 VB, promoting the separation of photoinduced charges, raising the quantum efficiency. When the molar ratio of In2O3/BWO is 2:6, the photocatalytic degradation degree of rhodamine B (RhB) is 59.4% (44.0% for BWO) after 60 min illumination, showing the best photocatalytic activity. After four cycles, the degradation degree of the sample was 54.3%, which is 91.4% of that of the first photocatalytic degradation experiment, indicating that the sample has good reusability. The XRD results of 2:6 In2O3/BWO before and after the cyclic experiments show that the positions and intensities of its diffraction peaks did not change significantly, indicating excellent structural stability. The active species experiment results imply that h+ is the primary species. Additionally, this study proposes a mechanism for the separation, migration, and photocatalysis of photoinduced charges in II-type semiconductor junctions.

Low-temperature hydrothermal self-assembly synthesis of ZnIn2S4/chitosan-graphene aerogels for enhanced aqueous pollutants removal

A novel visible-light-responsive ZnIn2S4/chitosan graphene aerogel (ZCGA) was prepared using a low-temperature hydrothermal self-assembly method for the adsorption and degradation of tetracycline. Infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) indicated interactions between ZnIn2S4 and chitosan graphene aerogel (CGA). Under the irradiation of a 500 W xenon lamp, ZCGA exhibited excellent adsorption and photocatalytic degradation performance for tetracycline, with a removal rate exceeding 90 % within 180 min. This significant performance improvement is attributed to the high carrier transport properties of CGA, which greatly enhanced the activity of the photocatalytic reaction and also showed high efficiency in removing other types of organic pollutants. Radical trapping experiments further confirmed that the superoxide anion (·O2−) is the main active species in the photocatalytic process. In addition, the monolithic aerogel has good recyclability and mechanical stability. This study not only demonstrates the great potential of ZCGA in the field of photocatalysis but also provides new ideas for designing efficient, recyclable, and visible light-responsive photocatalysts.

Application of MOFs in the Field of Photocatalysis

MOFs is the abbreviation of Metal organic Framework. Compared with the traditional inorganic metal materials, MOFs materials have the advantages of larger surface area, more diverse structure and function, and have been widely used in the field of photocatalysis. From the perspective of photocatalysis, this paper summarizes the application research process of MOFs material in the field of photocatalysis in the recent years, including photocatalytic decomposition of water to hydrogen production, photocatalytic decomposition of carbon dioxide, degradation of pollutants and so on. The application prospect of MOFs materials is prospected.

Electronic and photocatalytic properties of Cu4 cluster-modified Ag/g-C3N4 single-atom catalysts: A hybrid DFT study

Increasing the active sites on the catalyst surface has been a key goal to increase the catalyst efficiency. This paper presents an efficient conversion of solar energy into chemical energy, realized by a Cu4 cluster-assisted single-atom catalyst (Ag-doped g-C3N4). The catalyst enhances charge transfer and light absorption, and the unique advantages of this approach in the field of photocatalysis are substantiated by density functional theory. Under the synergistic effect of Cu4 clusters, the electronic state density distribution of the Ag single-atom catalyst substrate is drastically altered, which realizes the increase of substrate active sites and rapid charge separation and transfer. Compared with the pristine substrate g-C3N4, the new electronic state distribution and the generation of impurity energy levels lead to the narrowing of the band gap from 2.77 to 1.83 eV, accelerating the transfer and separation of electrons and holes, and enlarging the visible light absorption range from 410 to 760 nm, thus improving the solar energy utilization. Despite the reduced band gap, the conduction and valance band edges of (Ag, Cu4) codoped g-C3N4 still have sufficient potential to split water. Therefore, to improve the photocatalytic performance under visible light, simultaneous codoping of the Ag single atom and Cu4 cluster on g-C3N4 is an effective strategy. The study provides theoretical support for further optimization of single-atom catalysts.

Strategy and Advancement in Hybrid Hydrogel and Their Applications: Recent Progress and Trends

Advancements in polymers have made significant contribution in diverse application‐oriented fields. The multidisciplinary application of polymers generates a range of strategies, which is applicable in a wide range of biomedicines. Polymeric compounds such as hydrogels have been explored globally as a potent biomaterial that can furnish essential attributes due to their three‐dimensional (3D) soft and highly hydrophilic polymeric network. These hydrogels have been used extensively in various applications due to their biocompatible, biodegradable, and biosorption nature. However, they have some limitations, owing to their soft nature, low mechanical properties, and unsatisfactory degradation profile. Therefore, there is a need to develop novel, stronger, and more durable hybrid hydrogels with enhanced biocompatible and multifunctional properties. The current review gives a broad spectrum of hybrid hydrogels with its importance and significance. Further, the review highlights the strategies of generation of hybrid hydrogels reinforced with nanomaterials, biomaterials, and nanobiocomposites along with their advantages and disadvantages. The review also features various applications of these hybrid hydrogels in the field of biomedicines, photocatalysis, agriculture, and food industry over the last 5 years. This review will give a comprehensive overview to researchers working in the field of hybrid hydrogels development.