Manganese-based nanomaterials promote synergistic photo-immunotherapy: green synthesis, underlying mechanisms, and multiple applications

Single phototherapy and immunotherapy have individually made great achievements in tumor treatment. However, monotherapy has difficulty in balancing accuracy and efficiency. Combining phototherapy with immunotherapy can realize the growth inhibition of distal metastatic tumors and enable the remote monitoring of tumor treatment. The development of nanomaterials with photo-responsiveness and anti-tumor immunity activation ability is crucial for achieving photo-immunotherapy. As immune adjuvants, photosensitizers and photothermal agents, manganese-based nanoparticles (Mn-based NPs) have become a research hotspot owing to their multiple ways of anti-tumor immunity regulation, photothermal conversion and multimodal imaging. However, systematic studies on the synergistic photo-immunotherapy applications of Mn-based NPs are still limited; especially, the green synthesis and mechanism of Mn-based NPs applied in immunotherapy are rarely comprehensively discussed. In this review, the synthesis strategies and function of Mn-based NPs in immunotherapy are first introduced. Next, the different mechanisms and leading applications of Mn-based NPs in immunotherapy are reviewed. In addition, the advantages of Mn-based NPs in synergistic photo-immunotherapy are highlighted. Finally, the challenges and research focus of Mn-based NPs in combination therapy are discussed, which might provide guidance for future personalized cancer therapy.

Spent Lithium-Ion Batteries Derived Co3O4 for Electrocatalytic Polyethylene Terephthalate Plastic Recycling

Spent lithium-ion batteries (LIBs) are an essential secondary resource containing valuable metal elements. Transforming spent LIBs into efficient catalysts through a simple process presents a promising strategy to address both metal resource scarcity and clean energy challenges. Herein, a deep eutectic solvent-assisted synthesis of Co3O4 material from spent LIBs is proposed. The obtained Co3O4 material possesses efficient and stable electrocatalytic activity for converting raw polyethylene terephthalate (PET) bottles into high-purity formic acid and terephthalic acid products under ambient conditions. As expected, the Co3O4 catalyst exhibits a high FE of 92 % with a concentration of produced potassium formate of 23.6 mM under alkaline conditions. This study presents a waste-treating-waste strategy for the simultaneous recovery of spent LIBs and PET waste in a greener manner.

Quantification of alkalinity of deep eutectic solvents based on (H-) and NMR

Alkaline deep eutectic solvents (DESs) have been widely employed across diverse fields. A comprehensive understanding of the alkalinity data is imperative for the comprehension of their performance. However, the current range of techniques for quantifying alkalinity is constrained. In this investigation, we formulated a series of alkaline DESs and assessed their basicity properties through a comprehensive methodology of Hammett functions alongside 1H NMR analysis. A correlation was established between the composition, structure and alkalinity of solvents. Furthermore, a strong linear correlation was observed between the Hammett basicity (H-) of solvents and initial CO2 adsorption rate. Machine learning techniques were employed to predict the significant impact of alkaline functional components on alkalinity levels and CO2 capture capacity. This study offers valuable insights into the design, synthesis and structure-function relationship of alkaline DESs.

Fluorine Induced In Situ Formation of High Valent Nickel Species for Ultra Low Potential Electrooxidation of 5-Hydroxymethylfurfural

The Nickel-based catalysts have a good catalytic effect on the 5-hydroxymethylfurfural electrooxidation reaction (HMFOR), but limited by the conversion potential of Ni2+ /Ni3+ , 1.35 V versus RHE, the HMF electrooxidation potential of nickel-based catalysts is generally greater than 1.35 V versus RHE. Considering fluorine has the highest Pauling electronegativity and similar atomic radius of oxygen, the introduction of fluorine into the lattice of metal oxides might promote the adsorption of intermediate species, thus improving the catalytic performance. F is successfully doped into the lattice structure of NiCo2 O4 spinel oxide by the strategy of hydrothermal reaction and low-temperature fluorination. As is confirmed by in situ electrochemical impedance spectroscopy and Raman spectroscopy, the introduction of F weakens the interaction force of metal-oxygen covalent bonds of the asymmetric MT -O-MO backbone and improves the valence of Ni in tetrahedra structure, which makes it easier to be oxidized to higher valence active Ni3+ under the action of electric field and promotes the adsorption of OH- , while the decrease of Co valence enhances the adsorption of HMF with the catalyst. Combining the above reasons, F-NiCo2 O4 shows superb electrocatalytic performance with a potential of only 1.297 V versus RHE at a current density of 20 mA cm-2 , which is lower than the most catalyst.

Roles of Apigenin and Nepetin in the Assembly Behavior and Cytotoxicity of Prion Neuropeptide PrP106-126

Development of potential inhibitors to prevent prion protein (PrP) fibrillation is a therapeutic strategy for prion diseases. The prion neuropeptide PrP106-126, a research model of abnormal PrP (PrPSc), presents similar physicochemical and biochemical characters to PrPSc, which is also a target of potential inhibitors against prion deposition. Many flavones have antioxidant, anti-inflammatory, and antibacterial properties, and they are applied in treating prion disorder and other amyloidosis as well. However, the inhibition mechanism of flavones on PrP106-126 fibrillation is still unclear. In the current work, apigenin and nepetin were used to suppress the aggregation of PrP106-126 and to alleviate the peptide-induced cytotoxicity. The results showed that apigenin and nepetin impeded the fibril formation of PrP106-126 and depolymerized the preformed fibrils. They were bound to PrP106-126 predominantly by hydrophobic and hydrogen bonding interactions. In addition, both flavones upregulated cell viability and decreased membrane leakage through reducing peptide oligomerization. The differences in inhibition and cell protection between the two small molecules were presumably attributed to the substitution of hydroxyl and methoxy groups in nepetin, which demonstrated the significant structure-function relationship of flavones with prion neuropeptide and the prospect of flavonoids as drug candidates against prion diseases.

Genetic analysis of longevity and their associations with fertility traits in Holstein cattle

The increase of longevity is intended to reduce involuntary culling rates, not extend the life span, and it reflects the ability of animals to successfully cope with the environment and disease during production. Sire model, animal model and repeatability animal models were used to estimate the (co) variance components of longevity and fertility traits. Six longevity and thirteen fertility traits were analysed, including herd life (HL), productive life (PL), number of days between first calving and the end of first lactation or culling (L1); number of days between first calving and the end of the second lactation or culling (L2); number of days between first calving and the end of the third lactation or culling (L3); number of days between first calving and the end of the fourth lactation or culling (L4); age at first service, age at first calving (AFC), the interval from first to last inseminations in heifer (IFLh), conception rate of first insemination in heifer, days open (DO), calving interval, gestation length, interval from calving to first insemination (ICF), interval from first to last inseminations in cow (IFLc), conception rate of first insemination in cow, calving ease (CE), birth weight, and calf survival. The estimated heritabilities (±SE) were 0.018 (±0.003), 0.015 (±0.003), 0.049 (±0.004), 0.025 (±0.003), 0.009 (±0.002) and 0.011 (±0.002) for HL, PL, L1, L2, L3 and L4, respectively. Strong correlations were appeared in HL and PL; the genetic and phenotypic correlation coefficients were 0.998 and 0.985, respectively. There were high genetic and phenotypic correlations which were observed in L1 and L2, L2 and L3, L3 and L4, respectively. All fertility traits of heifer showed medium to high heritability, while the cow showed low heritability. All heifer fertility traits had low genetic associations with longevity traits, ranging from -0.018 (L2 and IFLh) to 0.257 (L3 and AFC). Most of the fertility traits showed negative correlations with longevity traits in different parities, and we recommend DO, ICF, IFLc and CE as indirect indicators of longevity traits in dairy cows, but we also need to take into account the differences between parities.

Operando Forming of Lattice Vacancy Defect in Ultrathin Crumpled NiVW-Layered Metal Hydroxides Nanosheets for Valorization of Biomass

The 2D layered metal hydroxides (LMHs) have been developed for electrooxidation of 5-hydroxymethylfurfural (HMF). In this work, an effective strategy is proposed to tailor the electronic structure of active sites at the atomic level, which is by introducing defects into the lattice structure. As an example, a series of ultrathin crumpled ternary NiVW-LMH electrocatalysts with abundant lattice vacancies (denoted as NiVW_v -LMH) are prepared in this way. The introduction of tungsten (W) endows the catalyst with a special crumpled structure, which promotes the generation of lattice vacancies and thus exposes more unsaturated Ni activity sites. The NiVW_v -LMH displays superb performance in the electrooxidation of HMF. The Tafel slope for electrodehydrogenation of Ni²⁺ OH bond to Ni(OH)O species is 12.04 mV dec^-1 . The current density at 1.43 V versus reversible hydrogen electrode (RHE) toward the oxidation reaction of HMF reaches about 193 mA cm^-2 , which is better than most of the common electrocatalysts, with an 5.37-fold improvement compared with Ni(OH)₂ electrode. The preparation strategy demonstrates in this work can be useful for developing highly efficient electrocatalysts.

Analysis of the oxygen evolution activity of layered double hydroxides (LDHs) using machine learning guidance

Layered double hydroxides (LDHs) are excellent catalysts for the oxygen evolution reaction (OER) because of their tunable properties, including chemical composition and structural morphology. An interplay between these adjustable properties and other (including external) factors might not always benefit the OER catalytic activity of LDHs. Therefore, we applied machine learning algorithms to simulate the double-layer capacitance to understand how to design/tune LDHs with targeted catalytic properties. The key factors of solving this task were identified using the Shapley Additive explanation and cerium was identified as an effective element to modify the double-layer capacitance. We also compared different modelling methods to identify the most promising one and the results revealed that binary representation is better than directly applying atom numbers as inputs for chemical compositions. Overpotentials of LDH-based materials as predicted targets were also carefully examined and evaluated, and it turns out that overpotentials can be predicted when measurement conditions about overpotentials are added as features. Finally, to confirm our findings, we reviewed additional experimental literature data and used them to test our machine algorithms to predict LDH properties. This analysis confirmed the very credible and robust generalization ability of our final model capable of achieving accurate results even with a relatively small dataset.

Yet another perspective on hole interactions, part II: lp-hole vs. lp-hole interactions

Most of the experimental and theoretical work in hole interactions (HIs) is mainly focused on exploiting the nature and characteristics of σ and π-holes. In this perspective, we focus our attention on understanding the origin and properties of lone-pair holes. These holes are present on an atom opposite to its lone-pair region. Utilizing some new and old examples, such as X₃N/P⋯F^- (X = F/Cl/Br/I), F-Cl/Br/I⋯H₃P⋯NCH and H₃B-NBr₃ along with other molecular systems, we explored to what extent these lp-holes participate in lp-hole interactions, if they participate at all.

Deep Eutectic Solvent-Induced In Situ Etching and Phosphorization to Form Nickel Phosphides for Electrooxidation of 5-Hydroxymethylfurfural

The development of catalysts with relatively high current densities at low potentials for the electrooxidation of 5-hydroxymethylfurfural (HMF) is still challenging. In this study, an in situ deep eutectic solvent (DES) etching phosphorization strategy is developed to prepare nickel phosphides encapsulated in P,O-codoped carbon nanosheets (Ni-P@POC). The DES serves not only as an etchant to extract Ni²⁺ from the nickel foam, but also as a phosphorus source to form nickel phosphides in situ uniformly embedded in the carbon films to produce a sheet structure. The electrooxidation performance is further greatly improved by implementing an electrochemical activation step to transform Ni-P@POC into NiOOH/Ni-P@POC (t-Ni-P@POC). t-Ni-P@POC exhibits a low onset potential of 1.20 V vs. RHE and a high current density of 200 mA cm^-2 at 1.33 V vs. RHE for HMF electrooxidation, outperforming most reported catalysts. The as-developed DES etching phosphorization strategy offers a facile, flexible, and universal route for the design of high-performance catalysts with specific nanostructures.

A Weak Acidic and Strong Coordinated Deep Eutectic Solvent for Recycling of Cathode from Spent Lithium-Ion Batteries

The leaching and recycling of valuable metals via environmentally benign solvents is important because of the ever-increasing waste lithium-ion batteries, but it remains a challenge. Herein, a multi-functional deep eutectic solvent (DES) based on lactic acid (LA) and guanidine hydrochloride (GHC) was used to extract cobalt and lithium ions from LiCoO₂ . Due to the strong acidity (protons) and abundant chlorine coordinating ions of LA/GHC, the solubility of LiCoO₂ in LA/GHC could reach as high as 19.9 mg g^-1 (stirred at 80 °C for 24 h), and a little LiCoO₂ powder even could be dissolved at room temperature without stirring. Oxalic acid was used to strip and separate the oxalates of cobalt and lithium. Furthermore, LA/GHC could be recycled with a similar dissolving performance. This work avoided using corrosive acids and could be realized at low temperature (80 °C), making it energy-saving and cost-effective. It shows DESs have great potential in extracting strategically important metals from LiCoO₂ cathodes and provides an efficient and green alternative for sustainable recycling of spent lithium-ion batteries.

Calorimetric effect and thermokinetics in the formation process of a deep eutectic solvent

For the first time, we report the calorimetric effect and thermokinetics in the formation process of a model deep eutectic solvent (DES), ChCl:urea. Mixing of a 1-to-2 molar ratio of choline chloride and urea shows a rapid endothermic process under stirring. The rate constants and reaction orders are determined by analyzing the thermokinetic curves at several constant temperatures. Low activation energy and activation parameters demonstrate that the formation of this DES is a rapid process. Other thermodynamic parameters are also estimated.

Room-temperature conversion of CO2 into quinazoline-2,4(1H,3H)-dione using deep eutectic solvents at atmospheric pressure with high efficiency

Deep eutectic solvents are found to catalyze CO2 conversion to quinazoline-2,4(1H,3H)-dione at room temperature and atmospheric pressure with nearly 100% yields for the first time.

Acidity Scales of Deep Eutectic Solvents based on IR and NMR

Acidic deep eutectic solvents (ADESs) have been utilized in various applications. Clearly, it is crucial to obtain acidity information that could reveal the relationship with performance. However, appropriate methods of...

Thermal, chemical, electrochemical, radiolytic and biological stability of ionic liquids and deep eutectic solvents

Ionic liquids (ILs) and deep eutectic solvents (DESs) are regarded as two kinds of novel solvents with high tunability and they exist in liquid-state for a wide range of temperature....

Deep insights into the viscosity of deep eutectic solvents by an XGBoost-based model plus SHapley Additive exPlanation

This work proposes a data-driven model which could predict the viscosity of diverse DESs accurately and rapidly, and the model interpretation given by SHAP deepens the understanding of the viscosity of DESs.

Room-temperature dissolution of PbI2 by a PEGylated deep eutectic solvent with high efficiency

PEGylated deep eutectic solvents could dissolve toxic PbI2 efficiently at room temperature.

An emerging deep eutectic solvent based on halogen-bond

A new deep eutectic solvents (DES) driven by halogen-bond was exploited. A family of eutectic mixtures in liquid state were obtained by combination of quaternary ammonium salts and dihalogens. The...

Magnetic deep eutectic solvents: formation and properties

Deep eutectic solvents (DESs) have been well-known as novel solvents due to their unique properties, which are dispensable for the development of green chemistry in future. The CoCl2·6H2O and NiCl2·6H2O-based...

Correction: Eutectics: formation, properties, and applications

Correction for 'Eutectics: formation, properties, and applications' by Dongkun Yu et al., Chem. Soc. Rev., 2021, DOI: .

Eutectics: formation, properties, and applications

Various eutectic systems have been proposed and studied over the past few decades. Most of the studies have focused on three typical types of eutectics: eutectic metals, eutectic salts, and deep eutectic solvents. On the one hand, they are all eutectic systems, and their eutectic principle is the same. On the other hand, they are representative of metals, inorganic salts, and organic substances, respectively. They have applications in almost all fields related to chemistry. Their different but overlapping applications stem from their very different properties. In addition, the proposal of new eutectic systems has greatly boosted the development of cross-field research involving chemistry, materials, engineering, and energy. The goal of this review is to provide a comprehensive overview of these typical eutectics and describe task-specific strategies to address growing demands.

Deep eutectic solvent-assisted synthesis of porous Ni2CO3(OH)2/SiO2 nanosheets for ultra-efficient removal of anionic dyes from water

Wastewater treatment is a severe environment issue, especially the discharge of excessive synthetic dyestuffs in the aquatic environment. In this study, a facile binary deep eutectic solvothermal process plus silica surface modification was successfully applied for preparation of porous nanosheet Ni₂CO₃(OH)₂/SiO₂ composites. The composites show powerful anionic dyes removal ability due to the high specific surface areas, hydrogen bond connection, coordination effect and strong electrostatic interactions with anionic dyes. A maximum adsorption capacity of 2637 mg g^-1 at neutral pH (ca.7) and 303 K was achieved for Ni₂CO₃(OH)₂/SiO₂ composite to adsorb Congo red, a representative anionic dye. Moreover, the composite has an excellent specificity for anionic dyes and could maintain above 95% removal efficiency after 5 cycles. Therefore, the as-prepared nanocomposites could be qualified as candidates for industrial environmental remedy. Furthermore, the proposed material preparation strategy could be extended to fabricate various advanced energy and environmental materials.

Thermal properties and cold crystallization kinetics of deep eutectic solvents confined in nanopores

Herein, the phase behaviors of both bulk and confined deep eutectic solvents in controlled pore glasses were first investigated. Glass transition, cold crystallization and melting behaviors alter significantly in the nanopores due to the size effect and interfacial interactions. Kinetic analysis of the crystallization reveals increased effective activation energies and pre-exponential factors under nanoconfinement.

High volatility of superbase-derived eutectic solvents used for CO2 capture

High volatility would lead to a highly flammable hazard, explosion danger, low regeneration efficiency and air pollution. Eutectic solvents (ESs) are assumed to be nonvolatile; however, the assumption is not correct. Here, we, for the first time, find that superbase-derived ESs are highly volatile. Even at room temperature (i.e., 25 °C) and atmospheric pressure, the mass loss of ESs could reach as high as 43.5% after 20 h of exposure. Superbase-derived ESs are promising solvents for CO2 capture, and they are also highly volatile after CO2 capture. We found that typical ethylene glycol : 1,8-diazabicyclo[5.4.0]undec-7-ene (EG : DBU (4 : 1)) has a three-stage volatilizing mechanism. EG and DBU volatilize first by breaking weak hydrogen-bonding interactions (1st stage), followed by the destruction of strong hydrogen-bonding interactions (2nd stage), and finally by destroying much stronger hydrogen-bonding interactions (3rd stage). This work presents a new horizon that ESs and their mixture with CO2 are highly volatile, which is helpful for mitigating laboratory explosion, combustion hazards, air pollution and designing new types of ESs with negligible volatility.

CO2 switchable deep eutectic solvents for reversible emulsion phase separation

CO₂ switchable imidazole-based deep eutectic solvents (DESs) were formed and used for reversible phase separation of emulsions generated between DESs and oil.

CO2 -Assisted Fabrication of Defect-Engineered Carbon Nitride for Enhanced Electrocatalytic Hydrogen Evolution

Here, a defect-engineered carbon nitride (DCN) electrocatalyst has been synthesized by directly annealing of a rationally designed urea precursor. The existence of defect sites was investigated by detailed characterizations. When loading a small amount of Ru nanoparticles, the obtained DCN catalyst offers excellent catalytic activity for electrochemical hydrogen evolution reaction.

Highly Efficient Cleavage of Ether Bonds in Lignin Models by Transfer Hydrogenolysis over Dual-Functional Ruthenium/Montmorillonite

Cleavage of ether bonds is a crucial but challenging step for lignin valorization. To efficiently realize this transformation, the development of robust catalysts or catalytic systems is required. In this study, montmorillonite (MMT)-supported Ru (denoted as Ru/MMT) is fabricated as a dual-functional heterogeneous catalyst to cleave various types of ether bonds through transfer hydrogenolysis without using any additional acids or bases. The prepared Ru/MMT material is found to efficiently catalyze the cleavage of various lignin models and lignin-derived phenols; cyclohexanes (fuels) and cyclohexanols (key intermediates) are the main products. The synergistic effect between electron-enriched Ru and the acidic sites on MMT contributes to the excellent performance of Ru/MMT. Systematic studies reveal that the reaction proceeds through two possible reaction pathways, including the direct cleavage of ether bonds and the formation of intermediates with one hydrogenated benzene ring, for all examined types of ether bonds, namely, 4-O-5, α-O-4, and β-O-4.

Eutectic Synthesis of High-Entropy Metal Phosphides for Electrocatalytic Water Splitting

High-entropy materials, a new class of alloys that incorporate five or more principal elements into single-phase crystal structures, have received considerable interest in materials science and engineering. Considering the tailored composition and disordered configuration, these high-entropy materials may arouse functional synergism towards electrocatalysis. Here, a new strategy for preparing high-entropy metal phosphides (HEMPs) was developed by a eutectic solvent method. The as-prepared HEMP possessed a single metal phosphide phase with up to five homogenously distributed metal components. The versatile application of high-entropy materials was highlighted by integrating the HEMP catalyst into a two-electrode configuration for electrocatalytic water splitting.

Rhodium-catalyzed reductive carbonylation of aryl iodides to arylaldehydes with syngas

The reductive carbonylation of aryl iodides to aryl aldehydes possesses broad application prospects. We present an efficient and facile Rh-based catalytic system composed of the commercially available Rh salt RhCl3·3H2O, PPh3 as phosphine ligand, and Et3N as the base, for the synthesis of arylaldehydes via the reductive carbonylation of aryl iodides with CO and H2 under relatively mild conditions with a broad substrate range affording the products in good to excellent yields. Systematic investigations were carried out to study the experimental parameters. We explored the optimal ratio of Rh salt and PPh3 ligand, substrate scope, carbonyl source and hydrogen source, and the reaction mechanism. Particularly, a scaled-up experiment indicated that the catalytic method could find valuable applications in industrial productions. The low gas pressure, cheap ligand and low metal dosage could significantly improve the practicability in both chemical researches and industrial applications.

Top-Down Extraction of Silk Protein Nanofibers by Natural Deep Eutectic Solvents and Application in Dispersion of Multiwalled Carbon Nanotubes for Wearable Sensing

With typical nanofibrous structure, silks spun by silkworms and spiders are the representative fibrous proteins that embody excellent mechanical properties and biological functions. However, it is still a challenge to directly extract silk nanofibers (SNFs) from natural silk fibers, to retain their nanostructures and properties, by a human- and environment-friendly approach for practical applications. Here, an all-natural strategy for simple, green, and scalable extraction of silkworm and spider silk protein nanofibers in natural deep eutectic solvents has been developed. The liquid-exfoliated SNFs have adjustable diameters from 20 nm (at the single SNF scale) to 100 nm and could be dispersed in water and organic solvents, enabling the production of useful macroscopic biomaterials. The free-standing SNF membranes made from silkworm silk nanofibers (SSNFs) exhibited cytocompatibility, flexibility, and excellent mechanical performance, providing the ability to fabricate sustainable materials for tissue engineering and green electronics. Moreover, the SSNF could be used as a green and efficient dispersant of multiwalled carbon nanotubes (MWCNTs), and the SSNFs/MWCNTs nanocomposite membranes could be used in wearable devices to monitor human activities.

Vaporization enthalpy, long-term evaporation and evaporation mechanism of polyethylene glycol-based deep eutectic solvents

PEG-based deep eutectic solvents are found to be highly volatile even at room temperature and atmospheric pressure.

Small organic molecules with tailored structures: initiators in the transition-metal-free C–H arylation of unactivated arenes

A small organic molecule was tailored for the efficient synthesis of biphenyl and its derivatives from aryl iodides.

Preparation of cyclic imides from alkene-tethered amides: application of homogeneous Cu(ii) catalytic systems

A Cu-based homogeneous catalytic system was proposed for the preparation of imides from alkene-tethered amides. Here, O₂ acted as a terminal oxidant and a cheap and easily available oxygen source. The cleavage of C Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> C bonds and the formation of C–N bonds were catalyzed by Cu(ii) salts with proper nitrogen-containing ligands under 100 °C. The synthesis approach has potential applications in pharmaceutical syntheses. Moreover, scaled-up experiments confirmed the practical applicability.

A catalytic system comprising Cu(ii) and a nitrogen-based ligand for the oxygenation and cyclization of alkene-tethered amides.

Ionicity of deep eutectic solvents by Walden plot and pulsed field gradient nuclear magnetic resonance (PFG-NMR)

The transport properties and ionicity of DESs were investigated by using Walden plot and the pulsed field gradient NMR method.

Fabricating Amorphous g-C3N4/ZrO2 Photocatalysts by One-Step Pyrolysis for Solar-Driven Ambient Ammonia Synthesis

Solar-driven nitrogen fixation remains a significant challenge. Graphitic carbon nitride (g-C₃N₄) is considered as a promising visible light photocatalyst. However, the photocatalytic performance of g-C₃N₄ is unsatisfactory because of the random transfer of charge carriers in the plane and the low activation efficiency of the reactants. Herein, amorphous ZrO₂ was used as a robust cocatalyst of g-C₃N₄ to increase the NH₃ production activity. The g-C₃N₄/ZrO₂ lamellar composites were constructed by a simple one-step pyrolysis of the deep eutectic solvent ZrOCl₂·8H₂O/urea. The optimum NH₄⁺ yield could reach as high as 1446 μmol·L^-1·h^-1 at 30 wt % ZrO₂ in the g-C₃N₄/ZrO₂ composites, with an apparent quantum efficiency over 2.14% at 400 nm. It is 7.9 times that of pristine g-C₃N₄ and 27.5 times that of ZrO₂. The introduction of amorphous ZrO₂ restrained the hydrogen generation, and the amorphous ZrO₂ and g-C₃N₄ together contribute to the rapid photoproduced electron transfer of less electron-hole pair recombination.

Water absorption by deep eutectic solvents

Deep eutectic solvents are found to be highly hygroscopic when exposed to the atmosphere.