H2O2 Production Research Articles

Synergistic effect of lightning rod and piezo-photocatalysis in sea urchin-shape Zn-MOF-74@g-C3N4 step-scheme heterojunction for H2O2 production under visible light irradiation

Piezo-photocatalytic H2O2 production was an emerging environmental technology that could convert solar energy into green chemicals, garnering significant attention. This study combined lightning rod effect and piezo-photocatalysis to achieve H2O2 production through an indirect two-electron oxygen reduction reaction pathway. A composite catalyst, sea urchin-shaped Zn-MOF-74@g-C3N4, had a surface of spherical Zn-MOF-74 made up of graphite phase carbon nitride nanoneedles with high curvature tips. These tips could induce a “lightning rod effect” property, accelerating charge transfer and separation by guiding electron migration along the sharp tip direction. The piezo-photocatalytic process, along with the construction of step-scheme heterojunction, generated a dual electric field, significantly enhancing the separation and migration rate of photogenerated carriers. As a result, the prepared Zn-MOF-74@g-C3N4 demonstrated a higher H2O2 production rate under the synergistic effect of lightning rod and piezo-photocatalysis. Free radical trapping experiments were conducted on various active species to uncover the mechanism behind the piezo-photocatalytic dual electric field coupling to produce H2O2.

Construction of multi-functional S-Vacancy-Zn3In2S6/Bi-MOF S-scheme heterojunction containing interfacial chemical bonds for the efficient photocatalytic production of H2O2 and excellent photocatalytic degradation of OTC and TC

Designing outstanding S-scheme heterojunction photocatalysts for eliminating pharmaceutical pollution and energy dilemmas is an effective strategy for tackling the issue of global environmental pollution. Herein, the Zn3In2S6/Bi-MOF S-scheme heterojunction was prepared through a facile in-situ hydrothermal method. The Bi-S bonds were introduced into the interface of an S-vacancy-containing Zn3In2S6/Bi-MOF S-scheme heterojunction, which profoundly boosts migration and separation of photogenerated carriers as the highway for electron transfer. The practical significance of Zn3In2S6/Bi-MOF composites for environmental pollution control was assessed using oxytetracycline (OTC) and tetracycline (TC) as representative pharmaceutical pollutants. Simultaneously, the production performance of H2O2 as a new energy carrier was also evaluated to determine the multi-functionality of the Zn3In2S6/Bi-MOF composite. The H2O2 production rate of optimal proportion photocatalyst reaches 3689.94 μmol/g/h without using the sacrificial agent. In addition, it exhibited a photocatalytic degradation of OTC and TC efficiency of 88.1 % and 65.2 % within 60 min, respectively. The Zn3In2S6/Bi-MOF photocatalytic not only exhibits excellent cyclic stability but also has exceptional anti-interference properties-systematic elucidation of the effects of catalyst dosage, pH, and co-existing substances. The efficient photocatalytic production of H2O2 and the degradation of OTC/TC through Bi-S bonds and VS-modificatory S-scheme charge transfer offer valuable new perspectives for designing photocatalysts.

Fragmented Polymetric Carbon Nitride with Rich Defects for Boosting Electrochemical Synthesis of Hydrogen Peroxide in Alkaline and Neutral Media.

Electrocatalytic oxygen reduction reaction via 2e- pathway is a safe and friendly route for hydrogen peroxide (H2O2) synthesis. In order to achieve efficient synthesis of H2O2, it is essential to accurately control the active sites. Here, fragmented polymetric carbon nitride with rich defects (DCN) is designed for H2O2 electrosynthesis. The multi-type defects, including the sodium atom doping in six-fold cavities, the boron atom doping at N-B-N sites and the cyano groups, are successfully created. Owing to the synergistic effect of these defects, the fragmented DCN achieves a high H2O2 production rateof 2.28 mol gcat. -1 h-1 and a high Faradic efficiency of nearly 90 % in alkaline media at 0.4 V vs. RHE in H-type cell. In neutral media, the H2O2 concentration produced by DCN can reach 1815 μM within 6 h at a potential of 0.2 V vs. RHE, and the H2O2 production rate of DCN is 0.23 mol gcat. -1 h-1. In addition, DCN shows excellent long-term durability in alkaline and neutral media. This study provides a new approach for the development of the boron, nitrogen doped carbon-based electrocatalysts for H2O2 electrochemical synthesis.

A self-supplied hydrogen peroxide and nitric oxide-generating nanoplatform enhances the efficacy of chemodynamic therapy for biofilm eradication

Bacterial biofilms present a profound challenge to global public health, often resulting in persistent and recurrent infections that resist treatment. Chemodynamic therapy (CDT), leveraging the conversion of hydrogen peroxide (H2O2) to highly reactive hydroxyl radicals (•OH), has shown potential as an antibacterial approach. Nonetheless, CDT struggles to eliminate biofilms due to limited endogenous H2O2 and the protective extracellular polymeric substances (EPS) within biofilms. This study introduces a multifunctional nanoplatform designed to self-supply H2O2 and generate nitric oxide (NO) to overcome these hurdles. The nanoplatform comprises calcium peroxide (CaO2) for sustained H2O2 production, a copper-based metal–organic framework (HKUST-1) encapsulating CaO2, and l-arginine (l-Arg) as a natural NO donor. When exposed to the acidic microenvironment within biofilms, the HKUST-1 layer decomposes, releasing Cu2+ ions and l-Arg, and exposing the CaO2 core to initiate a cascade of reactions producing reactive species such as H2O2, •OH, and superoxide anions (•O2–). Subsequently, H2O2 catalyzes l-Arg to produce NO, which disperses the biofilm and reacts with •O2– to form peroxynitrite, synergistically eradicating bacteria with •OH. In vitro assays demonstrated the nanoplatform’s remarkable antibiofilm efficacy against both Gram-positive Methicillin-resistant Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa, significantly reducing bacterial viability and EPS content. In vivo mouse model experiments validated the nanoplatform’s effectiveness in eliminating biofilms and promoting infected wound healing without adverse effects. This study represents a breakthrough in overcoming traditional CDT limitations by integrating self-supplied H2O2 with NO’s biofilm-disrupting capabilities, offering a promising therapeutic strategy for biofilm-associated infection.

Chronic undernutrition impairs renal mitochondrial respiration accompanied by intense ultrastructural damage in juvenile rats

This study investigated whether chronic undernutrition alters the mitochondrial structure and function in renal proximal tubule cells, thus impairing fluid transport and homeostasis. We previously showed that chronic undernutrition downregulates the renal proximal tubules (Na++K+)ATPase, the main molecular machine responsible for fluid transport and ATP consumption. Male rats received a multifactorial deficient diet, the so-called Regional Basic Diet (RBD), mimicking those used in impoverished regions worldwide, from weaning to a juvenile age (3 months). The diet has a low content (8 %) of poor-quality proteins, low lipids, and no vitamins compared to control (CTR). We investigated citrate synthase activity, mitochondrial respiration (oxygraphy) in phosphorylating and non-phosphorylating conditions with different substrates/inhibitors, potential across the internal membrane (Δψ), and anion superoxide/H2O2 formation. The data were correlated with ultrastructural alterations evaluated using transmission electron microscopy (TEM) and focused ion beam scanning electron microscopy (FIB-SEM). Citrate synthase activity decreased (∼50 %) in RBD rats, accompanied by a similar reduction in respiration in non-phosphorylating conditions, maximum respiratory capacity, and ATP synthesis. The Δψ generation and its dissipation after carbonyl cyanide-4-(trifluoromethoxy) phenylhydrazone remained unmodified in the survival mitochondria. H2O2 production increased (∼100 %) after Complex II energization. TEM demonstrated intense matrix vacuolization and disruption of cristae junctions in a subpopulation of RBD mitochondria, which was also demonstrated in the 3D analysis of FIB-SEM tomography. In conclusion, chronic undernutrition impairs mitochondrial functions in renal proximal tubules, with profound alterations in the matrix and internal membrane ultrastructure that culminate with the compromise of ATP supply for transport processes.

Inorganic/organic hybrid interfacial internal electric field modulated charge separation of resorcinol-formaldehyde resin for boosting photocatalytic H2O2 production

The strategy of inorganic/organic semiconductor material hybridization is of great significance for the development of highly active photocatalysts. Resorcinol-formaldehyde (RF) resin with a special donor-acceptor (D-A) structure shows excellent performance in the photocatalytic production of H2O2. However, the lack of an internal driving force for the separation and transfer of photogenerated electrons and holes in RF resin greatly limits the performance of H2O2 production. Herein, an inorganic/organic hybrid core-shell structure ZnS@RF photocatalyst was prepared by directionally induced coating of RF resin shells of different thicknesses on the surface of monodisperse ZnS nanospheres. Consequently, the photocatalytic H2O2 performance of ZnS@RF with the optimal RF resin shell thickness reaches 367.9 μmol L−1, which is 69 and 2 times that of ZnS and HRF, respectively. Density functional theory (DFT) calculations and related characterization results collectively demonstrate that the excellent photocatalytic H2O2 production performance of ZnS@RF photocatalyst is mainly attributed to the internal electric field (IEF) formed at the hybrid interface of ZnS and RF heterojunction and the optimization of RF shell thickness, which significantly enhances the separation and transfer of photogenerated carriers and modulates the interfacial catalytic reaction kinetics. This work opens up an avenue for designing inorganic/organic hybrid heterojunction photocatalyst materials with excellent photocatalytic activity.

Pre-Coordination Induced Further Deamination to Create Inter-Chain Cross-Linking in Carbon Nitride for Enhanced Photocatalytic H2O2 Production.

Creating cross-linking to establish efficient inter-chain charge-transfer channels in carbon nitride represents a promising strategy for enhancing its photocatalytic capabilities. Molten salt-assisted calcining has emerged as a method for preparing cross-linked carbon nitrides. However, the precise influence of molten salts on the molecular structure of carbon nitride remains to be fully elucidated. Herein, we develop a KCl guided cross-linking reaction to preliminarily reveal the formation mechanism of cross-linking. The cross-linking reaction is initiated by the pre-coordination of amino groups with K+. Subsequent heating at high temperature converts the amino groups into chlorines. Then, dechlorination leads to the formation of cross-linking. Thus, this cross-linking reaction can be accurately described as a pre-coordination-induced, two-step deamination reaction. The pre-coordination step plays a pivotal role in the cross-linking process. Sufficient pre-coordination results in a relatively high cross-linking degree of the as-prepared CNK-2. Consequently, CNK-2 demonstrates a significantly enhanced photocatalytic H2O2 production, with a generation rate of 682 μmol L-1 h-1, about 59 times that of traditional carbon nitride.

Self-dispersion of photocatalysts at oil-water interface accelerates H2O2 production and separation

Enhancing the efficiency of photocatalytic charge transfer for H2O2 production and in situ separation of H2O2 from aqueous suspension are crucial, especially when sacrificial agents are involved, for the advancement of this environmental-friendly process. In this study, we propose that the production and separation of H2O2 can be significantly enhanced at a self-assembled tri-phase system (water/photocatalyst/benzyl alcohol) compared to the suspension system. To prove this, we have employed titania nanotube (TNT) as a representative photocatalyst with efficient oxygen adsorption and modified it with organic ligand (octadecyl phosphate, OPA) and nickel species to modulate its hydrophobicity and dispersity at the interface, resulting in improved H2O2 yield. The modified TNT photocatalyst demonstrates efficient H2O2 production reaching a concentration of 5.1 mM after 75 mins under optimized conditions and an initial rate of 7500 μmol/g/h within first 6 h that even exceeding reported noble metals modified TiO2 photocatalysts. This enhanced activity is attributed to multiple effects including homogeneous dispersion of photocatalyst at the oil-water interface, efficient O2 adsorption and transfer, separated redox reactions at different phases, timely diffusion of H2O2 into bulk aqueous solution, and potential solvent-induced polarization effect on charge transfer, which result from the special oil-water interface that stabilizing photocatalysts and inducing photocatalytic O2 reduction. As proof-of-concept demonstrations show successful photosynthesis of H2O2 using natural solar light followed by utilizing the generated pure H2O2 solution for bacteria inactivation, indicating that interfacial photocatalytic systems offer promising potential for green H2O2 synthesis and application.

Potassium/cyano group co-incorporation promotes 2e− ORR selectivity in porous ultrathin carbon nitride for photocatalytic H2O2 production

Photocatalysis is a promising strategy for the production of H2O2, but the promotion of 2e− ORR selectivity remains a challenging goal in this field. Herein, Potassium (K+), cyano groups (-C≡N) and porous ultrathin structures were introduced into g-C3N4 simultaneously by the hyphenated technique of gas template method and molten salt-assisted method. The K+ and -C≡N can broaden the light absorption range, improve the reduction ability and promote electron transfer of the catalyst. Additionally, the presence of a permeable ultrathin structure plays a crucial role in improving the specificity of the 2e− oxygen reduction reaction (ORR). Benefiting from the multiple advantages, the H2O2 yield of K+ intercalated cyano-rich porous ultrathin g-C3N4 (KUCN) reached 781.39 μM with an extraordinary 2e− ORR selectivity of 94.5% (0.30 V vs. RHE). Overall, this study presents a practical approach for designing catalysts based on g-C3N4 that exhibit a high selectivity for the 2e− ORR reaction.

Variation of Chemical Microenvironment of Pores in Hydrazone-Linked Covalent Organic Frameworks for Photosynthesis of H2O2.

Photocatalytic synthesis of H2O2 is an advantageous and ecologically sustainable alternative to the conventional anthraquinone process. However, achieving high conversion efficiency without sacrificial agents remains a challenge. In this study, two covalent organic frameworks (COF-O and COF-C) were prepared with identical skeletal structures but with their pore walls anchored to different alkyl chains. They were used to investigate the effect of the chemical microenvironment of pores on photocatalytic H2O2 production. Experimental results reveal a change of hydrophilicity in COF-O, leading to suppressed charge recombination, diminished charge transfer resistance, and accelerated interfacial electron transfer. An apparent quantum yield as high as 10.3 % (λ=420 nm) can be achieved with H2O and O2 through oxygen reduction reaction. This is among the highest ever reported for polymer photocatalysts. This study may provide a novel avenue for optimizing photocatalytic activity and selectivity in H2O2 generation.

Variation of Chemical Microenvironment of Pores in Hydrazone‐Linked Covalent Organic Frameworks for Photosynthesis of H2O2

AbstractPhotocatalytic synthesis of H2O2 is an advantageous and ecologically sustainable alternative to the conventional anthraquinone process. However, achieving high conversion efficiency without sacrificial agents remains a challenge. In this study, two covalent organic frameworks (COF−O and COF−C) were prepared with identical skeletal structures but with their pore walls anchored to different alkyl chains. They were used to investigate the effect of the chemical microenvironment of pores on photocatalytic H2O2 production. Experimental results reveal a change of hydrophilicity in COF−O, leading to suppressed charge recombination, diminished charge transfer resistance, and accelerated interfacial electron transfer. An apparent quantum yield as high as 10.3 % (λ=420 nm) can be achieved with H2O and O2 through oxygen reduction reaction. This is among the highest ever reported for polymer photocatalysts. This study may provide a novel avenue for optimizing photocatalytic activity and selectivity in H2O2 generation.

Vacancy-defect promoting blue LED-driven H2O2 synthesis on Zn0.4Cd0.6S without additional cocatalysts

Photocatalytic synthesis of hydrogen peroxide offers an effective solution to the energy crisis. The design and development of high-activity and low-cost photocatalysts are crucial for H2O2 production. In this work, Zn0.4Cd0.6S with abundant S vacancies (SV-ZCS) is developed for H2O2 photosynthesis under 405 nm LED illumination without additional cocatalysts. The S vacancies serve as photo-generated electron trap centers, effectively extending the lifetimes of photogenerated carriers and promoting the separation of photoelectric carriers. Additionally, SV-ZCS is endowed with enhanced light capture capability, enhancing the overall photocatalytic activity for H2O2 production. The results were in line with expectations, the SV-ZCS samples demonstrated a hydrogen peroxide (H2O2) productivity of 3902 μmol L-1 h-1 when subjected to visible light irradiation, representing a significant increase compared to that of ZCS (2840 μmol L-1 h-1 ). This work provides an effective strategy for preparing photocatalysts for efficient hydrogen peroxide production.

Zinc Seed Priming Alleviates Salinity Stress and Enhances Sorghum Growth by Regulating Antioxidant Activities, Nutrient Homeostasis, and Osmolyte Synthesis

Salinity is a serious abiotic stress that limits crop production and food security. Micronutrient application has shown promising results in mitigating the toxic impacts of salinity. This study assessed the impacts of zinc seed priming (ZSP) on the germination, growth, physiological and biochemical functioning of sorghum cultivars. The study comprised sorghum cultivars (JS-2002 and JS-263), salinity stress (control (0 mM) and 120 mM)), and control and ZSP (4 mM). Salinity stress reduced germination and seedling growth by increasing electrolyte leakage (EL: 60.65%), hydrogen peroxide (H2O2: 109.50%), malondialdehyde (MDA; 115.30%), sodium (Na), and chloride (Cl) accumulation and decreasing chlorophyll synthesis, relative water contents (RWC), total soluble proteins (TSPs), and potassium (K) uptake and accumulation. Nonetheless, ZSP mitigated the deleterious impacts of salinity and led to faster germination and better seedling growth. Zinc seed priming improved the chlorophyll synthesis, leaf water contents, antioxidant activities (ascorbate peroxide: APX, catalase: CAT, peroxidase: POD, superoxide dismutase: SOD), TSPs, proline, K uptake and accumulation, and reduced EL, MDA, and H2O2 production, as well as the accumulation of toxic ions (Na and Cl), thereby promoting better germination and growth. Thus, these findings suggested that ZSP can mitigate the toxicity of salinity by favoring nutrient homeostasis, antioxidant activities, chlorophyll synthesis, osmolyte accumulation, and maintaining leaf water status.

Insights into trehalose mediated physiological and biochemical mechanisms in Zea mays L. under chromium stress

BackgroundChromium (Cr) toxicity significantly threatens agricultural ecosystems worldwide, adversely affecting plant growth and development and reducing crop productivity. Trehalose, a non-reducing sugar has been identified as a mitigator of toxic effects induced by abiotic stressors such as drought, salinity, and heavy metals. The primary objective of this study was to investigate the influence of exogenously applied trehalose on maize plants exposed to Cr stress.ResultsTwo maize varieties, FH-1046 and FH-1453, were subjected to two different Cr concentrations (0.3 mM, and 0.5 mM). The results revealed significant variations in growth and biochemical parameters for both maize varieties under Cr-induced stress conditions as compared to the control group. Foliar application of trehalose at a concentration of 30 mM was administered to both maize varieties, leading to a noteworthy reduction in the detrimental effects of Cr stress. Notably, the Cr (0.5 mM) stress more adversely affected the shoot length more than 0.3mM of Cr stress. Cr stress (0.5 mM) significantly reduced the shoot length by 12.4% in FH-1046 and 24.5% in FH-1453 while Trehalose increased shoot length by 30.19% and 4.75% in FH-1046 and FH-1453 respectively. Cr stress significantly constrained growth and biochemical processes, whereas trehalose notably improved plant growth by reducing Cr uptake and minimizing oxidative stress caused by Cr. This reduction in oxidative stress was evidenced by decreased production of proline, SOD, POD, MDA, H2O2, catalase, and APX. Trehalose also enhanced photosynthetic activities under Cr stress, as indicated by increased values of chlorophyll a, b, and carotenoids. Furthermore, the ameliorative potential of trehalose was demonstrated by increased contents of proteins and carbohydrates and a decrease in Cr uptake.ConclusionsThe study demonstrates that trehalose application substantially improved growth and enhanced photosynthetic activities in both maize varieties. Trehalose (30 mM) significantly increased the plant biomass, reduced ROS production and enhanced resilience to Cr stress even at 0.5 mM.

Boosting acidic hydrogen peroxide electrosynthesis on 2D metal-organic framework nanosheets based on cobalt porphyrins

The 2-electron electrocatalytic oxygen reduction reaction (2e− ORR) to hydrogen peroxide (H2O2) represents a promising strategy to resolve the high energy consumption and increasing environmental concerns inherent in the traditional anthraquinone process. The acidic 2e− ORR has emerged as an exciting alternative for industrial-level H2O2 production, whereas is hampered by the inferior H2O2 selectivity due to the uncontrollable proton-coupled electron transfer processes in an acidic environment. Herein, an ultrathin 2D metal–organic frameworks (MOFs) nanosheet based on cobalt tetra(4-carboxyphenyl) porphine (Co-TCPP NSs) is designed to promote H2O2 selectivity up to 96.5 %, accompanied with a remarkable H2O2 generation rate of 4677.42 mg·L−1·h−1. Of note, the Co-TCPP NSs also demonstrate its potential for the electro-Fenton process with a cumulative H2O2 concentration of 1.21 wt%, highlighting its practical potential in portable H2O2 generation electrochemical devices for distributed applications. Our findings demonstrated that the efficient H2O2 electrosynthesis could be attributed to the attenuated *OOH adsorption over Co-N4 moiety on the Co-TCPP NSs, which consequently suppresses its further reduction to form H2O. This work highlights the potential of 2D MOF architecture for the 2e− ORR and provides an atomic-level insight into the enhanced H2O2 selectivity.

Sustainable H2O2 production via solution plasma catalysis

Clean production of hydrogen peroxide (H2O2) with water, oxygen, and renewable energy is considered an important green synthesis route, offering a valuable substitute for the traditional anthraquinone method. Currently, renewable energy-driven production of H2O2 mostly relies on soluble additives, such as electrolytes and sacrificial agents, inevitably compromising the purity and sustainability of H2O2. Herein, we develop a solution plasma catalysis technique that eliminates the need for soluble additives, enabling eco-friendly production of concentrated H2O2 directly from water and O2. Screening over 40 catalysts demonstrates the superior catalytic performance of carbon nitride interacting with discharge plasma in water. High-throughput density functional theory calculations for 68 models, along with machine learning using 29 descriptors, identify cyano carbon nitride (CCN) as the most efficient catalyst. Solution plasma catalysis with the CCN achieves concentrated H2O2 of 20 mmol L-1, two orders of magnitude higher than photocatalysis by the same catalyst. Plasma diagnostics, isotope labeling, and COMSOL simulations collectively validate that the interplay of solution plasma and the CCN accounts for the significantly increased production of singlet oxygen and H2O2 thereafter. Our findings offer an efficient and sustainable pathway for H2O2 production, promising wide-ranging applications across the chemical industry, public health, and environmental remediation.

Nitrogen-Site Engineering in Covalent Organic Frameworks for H2O2 Photogeneration via Dual Channels of Indirect Two-Electron O2 Reduction.

Photocatalytic H2O2 production is a green and sustainable route, but far from meeting the increasing demands of industrialization due to the rapid recombination of the photogenerated charge carriers and the sluggish reaction kinetics. Effective strategies for precisely regulating the photogenerated carrier behavior and catalytic activity to construct high-performance photocatalysts are urgently needed. Herein, a nitrogen-site engineering strategy, implying elaborately tuning the species and densities of nitrogen atoms, is applied for H2O2 photogeneration performance regulation. Different nitrogen heterocycles, such as pyridine, pyrimidine, and triazine units, are polymerized with trithiophene units, and five covalent organic frameworks (COFs) with distinct nitrogen species and densities on the skeletons are obtained. Fascinatingly, they photocatalyzed H2O2 production via dominated two-electron O2 reduction processes, including O2-O2 •‒-H2O2 and O2-O2 •‒-O2 1-H2O2 dual pathways. Just in the air and pure water, the multicomponent TTA-TF-COF with the maximum nitrogen densities triazine nitrogen densities exhibited the highest H2O2 production rate of 3343µmol g-1 h-1, higher than most of other reported COFs. The theoretical calculation revealed the higher activity is due to the easy formation of O2 •‒ and O2 1 in different catalytic process. This study gives a new insight into designing photocatalysis at atomic level.

Enhanced photocatalytic performance of CdZnS nanoparticles and attapulgite/carbon nitride composites by carbon quantum dots mediated facilitated charge separation/transfer: Cr(VI) reduction and H2O2 production

In this work, CdZnS@carbon quantum dots/amino-modified attapulgite/carbon nitride (CdZnS@CQDs/M-ATP/PCN), function as Z-scheme heterojunction photocatalysts, have been successfully prepared by the hydrothermal method. CdZnS@CQDs-1/M-ATP/PCN-1 was optimized toward reduction of Cr(VI) and production of H2O2 under visible light, showing significantly improved photocatalytic performance. After coupling of M-ATP/PCN-1 with CdZnS and a moderate addition of CQDs, the synergistic formation of Z-scheme heterojunctions photocatalytic system effectively enhanced the photocatalytic properties of the composites. The results revealed that the CdZnS@CQDs/M-ATP/PCN catalysts contain rich active centers and suitable energy band structures, which enable them to produce more OH and O2−. Additionally, they also absorb visible light strongly and thus effectively improves the photocatalytic activity. Specifically, the reduction of Cr(VI) by CdZnS@CQDs-1/M-ATP/PCN-1 catalyst was achieved greater than 97.6 %, along with the production of 719.32 μmol·L−1 H2O2. Combining density functional theory (DFT) calculations, experimental test results and characterizations, we find that the excellent photocatalytic performance is attributed to the incorporation of CQDs and the formation of Z-scheme heterojunctions. We have developed a non-precious metal-based efficient Z-scheme photocatalytic system using simple hydrothermal synthesis method, which has a very high potential for energy production, environmentally sustainable remediation, and water purification.

Wheat Leaf Rust Fungus Effector Protein Pt1641 Is Avirulent to TcLr1.

Wheat leaf rust fungus is an obligate parasitic fungus that can absorb nutrients from its host plant through haustoria and secrete effector proteins into host cells. The effector proteins are crucial factors for pathogenesis as well as targets for host disease resistance protein recognition. Exploring the role of effector proteins in the pathogenic process of Puccinia triticina Eriks. (Pt) is of great significance for unraveling its pathogenic mechanisms. We previously found that a cysteine-rich effector protein, Pt1641, is highly expressed during the interaction between wheat and Pt, but its specific role in pathogenesis remains unclear. Therefore, this study employed techniques such as heterologous expression, qRT-PCR analysis, and host-induced gene silencing (HIGS) to investigate the role of Pt1641 in the pathogenic process of Pt. The results indicate that Pt1641 is an effector protein with a secretory function and can inhibit BAX-induced programmed cell death in Nicotiana benthamiana. qRT-PCR analyses showed that expression levels of Pt1641 were different during the interaction between the high-virulence strain THTT and low-virulence strains FGD and Thatcher, respectively. The highest expression level in the low-virulence strain FGD was four times that of the high-virulence strain THTT. The overexpression of Pt1641 in wheat near-isogenic line TcLr1 induced callose deposition and H2O2 production on TcLr1. After silencing Pt1641 in the Pt low-virulence strain FGD on wheat near-isogenic line TcLr1, the pathogenic phenotype of Pt physiological race FGD on TcLr1 changed from ";" to "3", indicating that Pt1641 plays a non-toxic function in the pathogenicity of FGD to TcLr1. This study helps to reveal the pathogenic mechanism of wheat leaf rust and provides important guidance for the mining and application of Pt avirulent genes.

Tris(triazolo)triazine‐Based Covalent Organic Frameworks for Efficiently Photocatalytic Hydrogen Peroxide Production

AbstractTwo‐dimensional covalent organic frameworks (2D‐COFs) have recently emerged as fascinating scaffolds for solar‐to‐chemical energy conversion because of their customizable structures and functionalities. Herein, two tris(triazolo)triazine‐based COF materials (namely COF‐JLU51 and COF‐JLU52) featuring large surface area, high crystallinity, excellent stability and photoelectric properties were designed and constructed for the first time. Remarkably, COF‐JLU51 gave an outstanding H2O2 production rate of over 4200 μmol g−1 h−1 with excellent reusability in pure water and O2 under one standard sun light, that higher than its isomorphic COF‐JLU52 and most of the reported metal‐free materials, owing to its superior generation, separation and transport of photogenerated carriers. Experimental and theoretical researches prove that the photocatalytic process undergoes a combination of indirect 2e− O2 reduction reaction (ORR) and 4e− H2O oxidation reaction (WOR). Specifically, an ultrahigh yield of 7624.7 μmol g−1 h−1 with apparent quantum yield of 18.2 % for COF‐JLU52 was achieved in a 1 : 1 ratio of benzyl alcohol and water system. This finding contributes novel, nitrogen‐rich and high‐quality tris(triazolo)triazine‐based COF materials, and also designate their bright future in photocatalytic solar transformations.