Clustering-resistant Cu Single Atoms on Porous Au Nanoparticles Supported by TiO2 for Sustainable Photoconversion of CO2 into CH4.

Photocatalysts based on single atoms (SAs) modification can lead to unprecedented reactivity with recent advances. However, the deactivation of SAs-modified photocatalysts remains a critical challenge in the field of photocatalytic CO2 reduction. In this study, we unveil the detrimental effect of CO intermediates on Cu single atoms (Cu-SAs) during photocatalytic CO2 reduction, leading to clustering and deactivation on TiO2. To address this, we developed a novel Cu-SAs anchored on Au porous nanoparticles (CuAu-SAPNPs-TiO2) via a vectored etching approach. This system not only enhances CH4 production with a rate of 748.8 µmol·g-1·h-1 and 93.1% selectivity but also mitigates Cu-SAs clustering, maintaining stability over 7 days. This sustained high performance, despite the exceptionally high efficiency and selectivity in CH4 production, highlights the CuAu-SAPNPs-TiO2 overarching superior photocatalytic properties. Consequently, this work underscores the potential of tailored SAs-based systems for efficient and durable CO2 reduction by reshaping surface adsorption dynamics and optimizing the thermodynamic behavior of the SAs.

Well-defined diatomic catalysis for photosynthesis of C2H4 from CO2.

Owing to the specific electronic-redistribution and spatial proximity, diatomic catalysts (DACs) have been identified as principal interest for efficient photoconversion of CO2 into C2H4. However, the predominant bottom-up strategy for DACs synthesis has critically constrained the development of highly ordered DACs due to the random distribution of heteronuclear atoms, which hinders the optimization of catalytic performance and the exploration of actual reaction mechanism. Here, an up-bottom ion-cutting architecture is proposed to fabricate the well-defined DACs, and the superior spatial proximity of CuAu diatomics (DAs) decorated TiO2 (CuAu-DAs-TiO2) is successfully constructed due to the compact heteroatomic spacing (2-3 Å). Owing to the profoundly low C-C coupling energy barrier of CuAu-DAs-TiO2, a considerable C2H4 production with superior sustainability is achieved. Our discovery inspires a novel up-bottom strategy for the fabrication of well-defined DACs to motivate optimization of catalytic performance and distinct deduction of heteroatom synergistically catalytic mechanism.

Infrared light dual excitation of Ni-phytate-sensitized ZnIn2S4 with sulfur vacancies for enhanced NIR-driven photocatalysis.

Near-infrared (NIR) light accounts for about half of the solar spectrum, and the effective utilization of low-energy NIR light is an important but challenging task in the field of photocatalysis. Molecular semiconductor photocatalytic systems (MSPSs) are highly tunable, available and stable, and are considered to be one of the most promising ways to achieve efficient NIR hydrogen production. Here, we demonstrate efficient dual-excitation in MSPS consisting of ZnIn2S4-x (ZIS1-x) with sulfur vacancies and phytic acid nickel (PA-Ni), which differs from other NIR-responsive photosensitized systems. The system achieves a hydrogen evolution reaction (HER) of 119.85 µmol h-1 g-1 at λ > 800 nm illumination, which is an excellent performance among all reported NIR catalysts and even outperforms the noble metal catalysts when compared to the reported literature. The superior activity is attributed to the unique charge dynamics and higher carrier concentration of the system. This work demonstrates the potential of dual-excitation systems for efficient utilization of low-energy NIR light.

Polymer Photocatalysts Containing Segregated π-Conjugation Units with Electron-Trap Activity for Efficient Natural-light-driven Bacterial Inactivation.

Development of highly efficient and metal-free photocatalysts for bacterial inactivation under natural light is a major challenge in photocatalytic antibiosis. Herein, we developed an acidizing solvent-thermal approach for inserting a non-conjugated ethylenediamine segment into the conjugated planes of 3,4,9,10-perylene tetracarboxylic anhydride to generate a photocatalyst containing segregated π-conjugation units (EDA-PTCDA). Under natural light, EDA-PTCDA achieved 99.9 % inactivation of Escherichia coli and Staphylococcus aureus (60 and 45 min), which is the highest efficiency among all the natural light antibacterial reports. The difference in the surface potential and excited charge density corroborated the possibility of a built-in electron-trap effect of the non-conjugated segments of EDA-PTCDA, thus forming a highly active EDA-PTDA/bacteria interface. In addition, EDA-PTCDA exhibited negligible toxicity and damage to normal tissue cells. This catalyst provides a new opportunity for photocatalytic antibiosis under natural light conditions.

Visible-light-driven photoreforming of poly(ethylene terephthalate) plastics via carbon nitride porous microtubes.

It is highly desirable but challenging to realize efficient photoreforming of plastic waste over metal-free semiconductors. Here, we synthesized metal-free carbon nitride porous microtube (CNxPM) photocatalysts by carrying out a pyrolysis of the supramolecular assembly formed by the self-assembly of L-arginine (L-Arg) and melamine, the modification of L-Arg rationally engineering the microstructure and electronic structure of the CNxPM system for efficient visible-light-driven photoreforming of poly(ethylene terephthalate) (PET) to hydrogen (H2) and high-value chemicals. In particular, the amount of formate converted from PET substrate under visible light was highest in metal-free semiconductors without any co-catalyst reported so far, presenting the first example of visible-light-driven photoreforming of PET over a completely metal-free single-component semiconductor without any co-catalyst.

Co(OH)2 water oxidation cocatalyst-decorated CdS nanowires for enhanced photocatalytic CO2 reduction performance.

Photocatalytic CO2 reduction is a promising technology to resolve the greenhouse effect and energy crisis. In this work, a Co(OH)2 nanoparticle decorated CdS nanowire (Co(OH)2/CdS) based heterostructured photocatalyst was prepared via a solvothermal and subsequent co-precipitation method, and it was used for photocatalytic CO2 reduction. The optimal Co(OH)2/CdS photocatalyst achieves a CO production rate of 8.11 µmol g-1 h-1 under visible light irradiation (λ > 420 nm), which is about 2 times higher than that of bare CdS. The experimental results show that a Co(OH)2 cocatalyst possesses a great capability of consuming holes, which promotes the oxygen-producing half-reaction and accelerates charge separation, thus enhancing the CO2 photoreduction performance of CdS. Notably, without using complex synthesis processes, hazardous substances or expensive ingredients, Co(OH)2/CdS shows high light absorption, efficient charge separation and complete CO product selectivity. This work offers a new pathway for the construction of cost-effective photocatalytic materials to achieve highly efficient CO2 reduction activity by the integration of a Co(OH)2 cocatalyst.

Integrating Ru-modulated CoP nanosheets binary co-catalyst with 2D g-C3N4 nanosheets for enhanced photocatalytic hydrogen evolution activity.

Developing high-efficient and low-cost photocatalysts is of great significance yet challenging for photocatalytic hydrogen evolution. Herein, we report a 2D/2D Ru-modulated CoP nanosheets (Ru-CoP-x, where x refers the Ru-to-Co molar ratio)/g-C3N4 nanosheets (GCN NSs) ternary hybrid as a photocatalyst for hydrogen evolution under visible light. The optimal photocatalyst 25% Ru-CoP-1:8/GCN NSs exhibits an excellent hydrogen evolution rate of 1172.5 µmol g-1 h-1 under visible light with a high apparent quantum efficiency (AQE) of 3.49% at 420 nm, which is close to Pt/g-C3N4 photocatalytic system and higher than most reported transition metal phosphides (TMP)/g-C3N4 photocatalytic system. Experimental results indicate that the higher photocatalytic hydrogen evolution performance can be mainly attributed to the binary Ru-CoP-x co-catalyst with efficient charge separation and promoted surface water reduction kinetics, and the 2D/2D self-assembly structure with strong interface Schottky effect and short charge transport distance. This study provides a new approach to develop cost-effective Pt-alternative co-catalysts for photocatalytic hydrogen evolution by incorporating a small amount of ruthenium into the transition metal phosphides.

Noble-metal-free Co x P nanoparticles: modified perovskite oxide ultrathin nanosheet photocatalysts with significantly enhanced photocatalytic hydrogen evolution activity.

The integration of semiconductor-based photocatalysts with noble-metal-free cocatalysts has great significance for practical applications. In this work, for the first time, novel Co x P/K+Ca2Nb3O10 - nanostructures (abbreviated as Co x P/KCNOus) were synthesized by integrating noble-metal-free Co x P nanoparticles onto the surface of K+Ca2Nb3O10 - ultrathin nanosheets (abbreviated as KCNOus), and exhibited enhanced photocatalytic hydrogen generation. Under the irradiation of xenon light, the hydrogen generation rate of the resulting optimal Co x P/KCNOus reached up to 90.4 µmol g-1 h-1, approximately 5.78 times higher than that of single-component KCNOus. The apparent quantum efficiency (AQE) of Co x P/KCNOus is 1.32% at 350 nm. Based on photoluminescence (PL), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), and photo-electrochemical analyses, possible reasons for this improved photocatalytic activity can be ascribed to the enhanced light absorption capacity and strong separation efficiency of photoinduced carriers over Co x P/KCNOus owing to the formation of the interfaces between KCNOus and Co x P nanoparticles. It is believed that this work will provide a new insight into the development ofefficient and low-cost noble-metal-free cocatalysts for photocatalytic hydrogen evolution reactions.

Seasonal changes in soil acidity and related properties in ginseng artificial bed soils under a plastic shade.

BACKGROUND: In Changbai Mountains, Panax ginseng (ginseng) was cultivated in a mixture of the humus and albic horizons of albic luvisol in a raised garden with plastic shade. This study aimed to evaluate the impact of ginseng planting on soil characteristics. METHODS: The mixed-bed soils were seasonally collected at intervals of 0-5 cm, 5-10 cm, and 10-15 cm for different-aged ginsengs. Soil physico-chemical characteristics were studied using general methods. Aluminum was extracted from the soil solids with NH4Cl (exchangeable Al) and Na-pyrophosphate (organic Al) and was measured with an atomic absorption spectrophotometer. RESULTS: A remarkable decrease in the pH, concentrations of exchangeable calcium, NH4 (+), total organic carbon (TOC), and organic Al, as well as a pronounced increase in the bulk density were observed in the different-aged ginseng soils from one spring to the next. The decrease in pH in the ginseng soils was positively correlated with the [Formula: see text] (r = 0.463, p < 0.01), exchangeable calcium (r = 0.325, p < 0.01) and TOC (r = 0.292, p < 0.05) concentrations. The [Formula: see text] showed remarkable surface accumulation (0-5 cm) in the summer and even more in the autumn but declined considerably the next spring. The exchangeable Al fluctuated from 0.10 mg g(-1) to 0.50 mg g(-1) for dry soils, which was positively correlated with the [Formula: see text] (r = 0.401, p < 0.01) and negatively correlated with the TOC (r = -0.329, p < 0.05). The Al saturation varied from 10% to 41% and was higher in the summer and autumn, especially in the 0-5 cm and 5-10 cm layers. CONCLUSION: Taken together, our study revealed a seasonal shift in soil characteristics in ginseng beds with plastic shade.