Addition Of NaCl Research Articles

Accumulation of reactive carbonyl species in roots as the primary cause of salt stress‐induced growth retardation of Arabidopsis thaliana

AbstractSalt stress on plants induces an increase in reactive oxygen species (ROS), which then leads to the formation of reactive carbonyl species (RCS) such as acrolein and 4‐hydroxy‐(E)‐2‐nonenal (HNE), potent cytotoxins generated from lipid peroxides. We recently showed that salt‐stress treatment of Arabidopsis thaliana plants increased RCS levels, and exogenously added RCS‐scavenging chemicals alleviated the stress symptoms, indicating that RCS were responsible for the tissue damage in salt‐stressed plants. To obtain deeper insights into the role of RCS in stressed plants, we here analyzed changes in the levels of various RCS in the roots and shoots of A. thaliana. NaCl (90 mM) addition to the culture medium as a salt‐stress treatment caused growth inhibition and leaf chlorosis. Carbonyl analysis using HPLC revealed that the stress treatment induced a 2‐fold increase in the root levels of RCS, including acrolein, HNE and 4‐hydroxy‐(E)‐2‐hexenal (HHE). In the shoots, basal levels and stress‐induced increases of the RCS were lower than in roots. In the transgenic A. thaliana plants that overexpress the RCS‐scavenging enzyme 2‐alkenal reductase (AER) cDNA under the β‐estradiol (β‐ED)‐responsive promoter, salt stress induced less damage than in the wild‐type under β‐ED supplementation. The AER overexpression suppressed the stress‐induced increases in HNE, acrolein, HHE and (E)‐2‐hexenal in roots and in HNE in leaves, but not the ROS increase. These results suggest that the RCS increase in roots was the primary cause of salt‐induced damages. Enhancing RCS‐scavenging abilities, such as by AER overexpression, could be a new strategy to confer salt‐stress tolerance to plants.

A Study of the Effects of Saltwater on the Formation, Curing and Strength of Concrete

Concrete is extensively used in all construction works such as buildings, bridges, roads and dams worldwide. It is made by simply combining cement, aggregate, sand and water in the appropriate proportion. This paper explores the investigational study on the outcome of using saltwater in coastal regions for blending and curing concrete since palatable water is a deficient asset on the earth. As most of the ions in seawater comprise Na, Mg, Cl- and SO42-, this research aimed to observe how concrete behaves after the addition of NaCl and MgSO4 salt separately for mixing concrete and curing at different concentrations. Concrete cylinders were cured using fresh water as well as saltwater separately. A total specimen of 42 cylinders was cast with 100%, 75% and 50% ion concentrations of NaCl, MgSO4 and freshwater specimens prepared for the reference concrete, which were exhibited for 7 days and 28 days of curing. A comparatively higher compressive strength was found for a 50% salt concentration of MgSO4 and for 75% salt concentration of NaCl. The comparison of compressive strength using NaCl and MgSO4 samples between this research and previous researches was derived for 7 days and 28 days. A correlation between the compressive strength and ion concentrations of NaCl and MgSO4 for 28 days was derived by performing linear regression analysis. The relations obtained by this analysis can be utilized for further prediction of compressive strength at any other ion concentrations of these salts. IUBAT Review, 6(2): 25-40

Preparation of high internal phase pickering emulsions using micron-sized esterified maize starch as the sole effective stabilizer

Preparation of high internal phase Pickering emulsions (HIPPEs) from starch nanocrystals (SNCs) is currently a key area of research. However, the high cost of producing SNCs restricts their usage in the food industry. This study investigated the effectiveness of micron-sized esterified maize starch (M-NMS) as the sole stabilizer for the preparation of HIPPEs. It was found that stable, gel-like HIPPEs with an oil phase volume of 75–90% could be created by using M-NMS granules at a concentration of ≥3.0 wt%. At a pH of 5.0–9.0, the absolute value of zeta potential for all emulsions exceeded 61 mV, indicating high interfacial stability. The addition of NaCl at a concentration of 40–160 mmol/l had no significant effect on the emulsion's viscosity, viscoelasticity, or stability. The gel structure formed by the swollen M-NMS molecular chain predominantly determined the emulsion's performance, as shown by atomic force microscopy.

Effect of Sodium Chloride Concentration on Cooking Time Calculation and Sensory Evaluation of Fish Sausage

This research was conducted to evaluate the effect of the addition of sodium chloride (NaCl) at different concentrations (0–3.0%) on the theoretical and real cooking time and sensory evaluation of the fish sausage. The fish sausage was prepared using 2:1.2:1 minced fish, sago starch, and water with added NaCl at a concentration of 1.5% to the formulation, and the sausage was cooked for 180 seconds (3 min) at 180°C to accomplish both the correct cooking time and sensory evaluation properties. Theoretical and real cooking time methods were calculated using a pre-calibrated thermocouple to reach the target core temperature of 75oC at the centre of the sausage. The optimum NaCl concentration and cooking time were identified from the cooking methods and sensory evaluation. The results revealed that increasing the addition of NaCl to the sausage formulations significantly increased the core temperature of the sausage during cooking. There was a reverse relationship between the added percentage of sodium chloride and the calculated cooking time; as the addition of sodium chloride increased, a shorter cooking time was obtained until we reached the target core temperature of 75oC. The predicted cooking time was 195.171 seconds, and the real cooking time was 180 seconds.

Evaluation of the efficiency of coconut dust extract as a corrosion inhibitor for steel reinforcement in concrete by mass spectrometry

Ethanol extraction was employed to isolate a range of compounds from waste products derived from coconut fiber production (coconut dust) in Ben Tre, Vietnam. Phytochemical screening confirmed the presence of flavonoids, tannins, polyphenols, saponins, alkaloids, flobatannins, and anthraquinones among the extracted substances. FT-IR spectroscopy analysis supported the identification of oxygen and nitrogen atoms within functional groups (e.g., O–H, N–H, C–O) and aromatic rings, characteristic of typical corrosion inhibitors. Mass spectrometry investigations indicated that when St3 steel was exposed to an alkaline solution lacking chlorides, a passive film composed of FeOOH formed on the surface. However, upon the addition of NaCl at a concentration of 1.00 mol/dm3, FeCl, FeCl2Cl–, and FeCl3Cl– compounds were detected across the analyzed surface, while peaks corresponding to FeOO– were absent. Remarkably, areas with the highest concentration of particles corresponded to regions exhibiting visible corrosion damage under magnification. The addition of 2.00 g/dm3 of coconut dust extract to the chloride solution prevents the formation of Fe and Cl compounds on the steel surface. Consequently, only peaks characteristic of FeOO– and organic fragments containing oxygen atoms from the extract were observed. Based on these results, it can be assumed that coconut dust extract has the potential to inhibit local (pitting) corrosion of low-carbon steel (St3) when exposed to aqueous alkaline solutions simulating concrete pore liquid containing chlorides. The addition of 2.00 g/dm3 of the extract has been shown to prevent pitting formation at a chloride concentration of 1.00 mol/dm3. Conversely, in the absence of the extract, visible local corrosion damage was observed upon magnification. These findings provide a basis for further exploration of the protective properties of coconut dust extract as an environment-friendly corrosion inhibitor for mild steel in concrete environments containing chlorides.

Enhancing Resistance to Salinity in Wheat by Using Streptomyces sp. HU2014

Salt stress affects the growth and global production of wheat (Triticum aestivum L.). Plant growth-promoting microbes can enhance plant resistance to abiotic stresses. In this study, we aimed to assess the inoculation of soil with Streptomyces sp. HU2014 to improve wheat tolerance to salt stress from multiple perspectives, including the interaction of the strain, the addition of NaCl, the condition of the wheat, and rhizosphere microbial communities. The results showed that the strain promoted wheat growth under NaCl stress by increasing biomass by 19.8%, total chlorophyll content by 72.1%, proline content by 152.0%, and malondialdehyde content by 106.9%, and by decreasing catalase by 39.0%, peroxidase by 1.4%, and soluble sugar by 61.6% when compared to the control. With HU2014 soil inoculation, total nitrogen, nitrate nitrogen, total phosphorus, and Olsen phosphorus increased, whereas ammonium nitrogen and pH decreased. HU2014 inoculation and/or the addition of NaCl affected the diversity of rhizosphere bacteria, but not fungi. The structure of the microbial community differed after HU2014 inoculation, with Proteobacteria, Acidobacteriota, Bacteroidota, and unclassified fungi being the dominant phyla, and these taxa correlated with the above-mentioned soil parameters. Thus, this study provided a promising way to enhance wheat tolerance to salt stress and improve the agricultural ecological environment by using plant growth-promoting microbes.

The effect of coolant additives on the vapour explosion behaviour in melt droplet impingement experiments

Vapour explosions are a known hazard with potentially devastating consequences in several industries. They might occur when a hot liquid comes into direct contact with a cold and volatile liquid. Eutectic PbS-Cu2S droplet impingement experiments were performed to investigate the effect of the coolant composition on the vapour explosion behaviour. The composition was varied between water with systematic additions of NaCl, MEG, or a combination of both. The experiments were monitored with a hydrophone and a high-speed camera. Also, the resulting debris was sieved for further analysis. The investigation considered the trigger probability and explosion intensity. The latter was quantified via the size of the explosion, the height of the hydrophone signal, and the debris particle size. NaCl additions were found to increase both the trigger probability and the explosion intensity, whereas MEG additions were found to decrease the trigger probability and explosion intensity. However, combined additions of MEG and NaCl resulted in a decreasing trigger probability, while having an unclear effect on the explosion intensity.

Mung Bean Starch and Mung Bean Starch Sheet Jelly: NaCl-Based Characteristics Variation.

Empirical evidence indicates that NaCl can improve the quality of mung bean starch sheet jelly (MBSS) when properly incorporated. In this study, by comparison with a sample without NaCl, the influences of NaCl (1.5-8%, w/w) on the physicochemical and structural properties of mung bean starch (MBS) and the quality of MBSS were investigated. MBS with added NaCl had greater gelatinization temperature and pasting parameters but lower gelatinization enthalpy than native MBS. With the addition of NaCl, the drying rate of MBSS first accelerated and then declined in the oven-drying process. The addition of NaCl improved the cooking properties of MBSS but decreased the hardness of cooked MBSS. Rheological results implied that the linear viscoelastic region of cooked MBSS decreased with the NaCl addition, and the storage modulus and tan δ were more frequency-dependent than the loss modulus of cooked MBSS. The addition of NaCl gradually increased the toughness of dried MBSS and the overall acceptability of cooked MBSS. Furthermore, NaCl decreased the structure order degree of starch in MBSS. Correlation analysis demonstrated that the quality of MBSS had a significant correlation with the molecular and lamellar order of starch. Overall, NaCl could improve the quality of MBSS by regulating the thermal, gelatinizing, and structural properties of MBS.

Synergistic Stabilization of Nanoemulsion Using Nonionic Surfactants and Salt-Sensitive Cellulose Nanocrystals.

Soybean stover is a lignocellulose biomass that is rich in cellulose. In the present study, soybean cellulose nanocrystals (CNCs) were prepared from soybean stover by alkaline treatment, bleaching treatment, acid hydrolysis, dialysis and ultrasonication. The as-prepared soybean CNC was characterized by transmission electron microscopy (TEM), zetasizer and rheometer. The effects of NaCl on the particle size, zeta potential, and viscosity of soybean CNC was studied. Soybean CNC was explored as an emulsion stabilizer for lemongrass-essential-oil-loaded emulsions. Soybean CNCs could stabilize the oil-in-water emulsion against coalescence but not flocculation. The addition of NaCl reduced the creaming index and enhanced the encapsulation efficiency and freeze-thaw stability of the CNC-stabilized emulsion. Salted CNC (i.e., CNC in the presence of NaCl) enhanced the thermodynamic stability (i.e., heating-cooling and freeze-thaw stability) of Tween 80 stabilized emulsion, while unsalted CNC did not. Synergistic effects existed between Tween 80 and salted CNC in stabilizing oil-in-water emulsions. The nanoemulsion stabilized with Tween 80 and salted CNC had a mean particle size of ~70 nm, and it was stable against all thermodynamic stability tests. This is the first study to report the synergistic interaction between salted CNC and small molecular weight surfactants (e.g., Tween 80) to improve the thermodynamic stability of nanoemulsion.

EVALUATION OF METHODS FOR TOTAL RNA EXTRACTION FROM THE ENDOSPERM OF COCOS NUCIFERA VAR. MAKAPUNO IN VIETNAM FOR MOLECULAR ANALYSIS

Sap coconut (Cocos nucifera L. var. makapuno) in Vietnam is a mutant coconut variant; coconut water is in the state of lotus glue, and coconut rice is like cream. For high-quality transcriptome, sequencing, quality, purity and concentration of RNA are the key factors. However, coconut endosperm tissue has higher stiffness and fatness than the leaf tissue, which complicates the extraction process. Moreover, RNA is much more difficult to preserve than DNA. In this study, various RNA extraction methods were examined in Vietnamese waxy coconut endosperm tissue samples. Optimum extraction and preservation of the RNA using the simplest possible chemicals was the objective of this study. The modified CTAB method with LiCl and the TRI reagent method were tested and evaluated. The purity, concentration and quality of RNA after storage were improved. The findings indicated that the TRIsure extraction method with the addition of NaCl and β-mercaptoethanol yielded optimum RNA quality. The RNA concentration was 159 ng/µL, with a purity ratio of 1.94 ± 0.04 for A260/A280 and 1.58 ± 0.02 for A260/230. RNA samples remained stable for up to 3 weeks when stored in absolute ethanol at 8°C–10°C, which significantly reduced their degradation during transportation. This study facilitated the use of simple chemicals for high-quality RNA extraction from coconut endosperm and its preservation for applications in high throughput sequencing.

Effects of NaCl on the Physical Properties of Cornstarch-Methyl Cellulose Blend and on Its Gel Prepared with Rice Flour in a Model System.

This study investigated the impact of NaCl on the physical properties of cornstarch-methyl cellulose (CS-MC) mixtures and their gels prepared with rice flour in a model system. Opposite trends were observed, showing that NaCl led to decreased viscosity of the CS-MC mixtures (liquid-based), whereas a more stable and robust structure was observed for the rice-flour-added gels (solid-based) with the addition of NaCl. The interference of NaCl with the CS-MS blend's ability to form a stable gel network resulted in a thinner consistency, as the molecules of the CS-MS blend may not bind together as effectively. On the contrary, NaCl showed the potential to enhance the protein network within CS-MC gels prepared with rice flour, thereby contributing to an augmentation in the stability or firmness of the cooked gels. Careful utilization of NaCl to optimize the physical properties of the CS-MC blends, as well as the gels based on rice flour, should be performed.

Oxidative behaviour, aggregation and structural properties of silver carp myofibrillar proteins with different molecular states subjected to freeze–thaw process

SummarySilver carp myofibrillar proteins (MP) with different moleculars states were constructed by the addition of NaCl and fracture degree of muscle fibres. Results showed that salt‐dissolved MP (P+) under unfrozen and oxidised state showed higher oxidation degree with higher carbonyl (3.42 nmol mg−1) and dityrosine contents (25.98 a.u.) (P < 0.05) compared with saltless‐polymeric MP (P) and salt‐induced swelling MP (F+) due to addition of salt and broken muscle fibres. After oxidative and freeze–thaw process, P+ group also exhibited more cross‐linking as evidenced by turbidity (0.73), solubility (64.96%) and SDS‐PAGE, but unordered aggregates in P group increased probably due to severe frozen denaturation. Moreover, F+ group of salt‐induced swelling MP from intact muscle fibres suffered less structural damages with higher fluorescence intensity (668.41 a.u.) and higher α‐helix contents (15.56%). Overall, Fish‐ Hua of salt‐dissolved MP had a higher oxidation level and NaCl contributed to improve freeze–thaw stability of MP during freeze–thaw process.

Molecular dynamics study on the effect of inorganic salts on the wettability of surfactants on bituminous coal: Sodium dodecyl sulfate and sodium chloride as representatives

To further enhance the wetting ability of surfactants to coal, the mechanism of improving the wetting performance of SDS to bituminous coal by the addition of inorganic salt NaCl was studied through a combination of molecular dynamics (MD) simulation with experimental measurements. In the experiment part, the surface tensions of the mixed NaCl-SDS solutions and the contact angles on the bituminous coal surface were measured. Furthermore, MD simulations were conducted to investigate the adsorption characteristics and wetting mechanism of a mixed NaCl-SDS solution on the coal surface at the atomic scale. In this process, the static potentials of the H2O molecule, coal molecule and SDS molecule were calculated, and the number of hydrogen bonds (H-bonds) formed throughout the whole simulation process, the average H-bond length, the relative concentration distribution (RCD) curve and the mean square displacement (MSD) curve were obtained. The experimental results showed that the surface tension and contact angle were both decreased by the addition of sodium chloride in mixed solutions. When 0.6 mol/L NaCl was added, the surface tension and contact angle reached the minima of 30.45 mN/m and 13.01°, respectively. The MD simulation results showed that, after the addition of NaCl, diffusion and migration of H2O molecules were limited, the number of H-bonds increases, the average bond length decreased, the sorption between H2O molecules and coal molecules was enhanced, and the hydrophilicity of coal surface was improved, which meant that the wetting ability of SDS solution to bituminous coal was enhanced by adding NaCl. The effect of the added NaCl in improving the wettability of SDS on coal was explored from two perspectives with macroscopic experiments and microcosmic simulations, and the added NaCl improved the effects of dust suppressants, and played a key role in preventing dust hazards in coal mines.

Challenges in surface‐enhanced Raman scattering signal for ethephon detection: Theoretical and experimental approaches

AbstractEthephon, a widely used growth regulator in fruits and vegetables, requires careful monitoring because of its toxicity. However, as far as we know, only two works are found in the literature regarding surface‐enhanced Raman scattering (SERS) ethephon detection. Indeed, obtaining the SERS signal revealed to be challenging. Therefore, we have evaluated the SERS signal of ethephon using theoretical (as density functional theory and charge‐assisted fragment interaction) and experimental approaches, addressing this limited literature knowledge. Theoretical Raman spectra with Ag or Au atoms at reactive sites exhibited enhanced ethephon SERS signal via AgCl bonding, consistent with the experimental data. Multiple experimental procedures were employed to obtain the SERS signal, including pH variations, salt addition, excitation laser lines, time dependency, and different SERS substrates (Ag colloid and Ag island films). Salt addition (NaCl) improved SERS signal, correlating with Ag colloid aggregation. Analysis in Ag colloid showed the pH 7.0 as optimal for ethephon detection, using freshly prepared Ag colloid + ethephon dispersion with ethephon powder being directly dissolved into Ag colloid. Only the AgCl band intensity improved with time. Ag colloid (wet medium — 633 nm laser line) outperformed Ag island films (dry medium — 785 nm laser line).

The phase behavior of Isopropanol/Water/NaCl mixtures at atmospheric pressure and temperatures from 294.15 K up to the boiling point

Branched-chain higher alcohols (BCHAs) have potential applications in the preparation of biofuels as they have properties similar to those of gasoline. Isopropanol is the simplest member of the BCHA family and is produced by either a catalytic process or fermentation of biomass. Regardless of the process, the isopropanol is produced as a component of a mixture with water content as high as 80%; therefore, purification is needed to produce fuel-grade isopropanol. Azeotropic and heteroazeotropic distillation are currently used to purify the isopropanol but they are carbon-intensive and costly. The addition of NaCl to an isopropanol/water mixture has two effects: could trigger a liquid–liquid phase split; and increases the relative volatility of the alcohol. These effects could potentially be used as the departure for the design of low-carbon and less expensive purification operations.The phase behavior of isopropanol/water/NaCl mixtures was experimentally mapped at temperatures up to the boiling point at atmospheric pressure. The liquid–solid, liquid–liquid, liquid–liquid–solid, liquid–vapor, liquid–liquid–vapor, liquid–liquid–solid–vapor and liquid–solid–vapor regions were experimentally detected and located in the phase diagram. The equilibrium compositions within the liquid–liquid, liquid–vapor and liquid–liquid–solid–vapor regions were measured. Three well-known methods were employed to assess the reliability of the measured liquid–liquid phase compositions. The temperatures and the composition of the vapor phase in the liquid–liquid–vapor region were also experimentally measured. The collected experimental data was used to construct the phase diagram of isopropanol/water/NaCl mixtures at 5, 10 and 20 wt% NaCl content, at atmospheric pressure, and temperatures from 294.15 K to the boiling point.

Fibrous whey protein mediated homogeneous and soft-textured emulsion gels for elderly: Enhancement of bioaccessibility for curcumin

Homogeneous and soft-textured food gels are critical for designing precise and personalized nutrient food for elderly. Effects of whey protein morphology (fibrous and granular) with/without NaCl addition on oil-water state and texture properties of protein emulsion gels were investigated, to explore the feasibility of developing homogeneous and soft-textured food for elderly. Lower gelation temperature and higher stability of its emulsion droplets, resulted in fibrous whey protein emulsion gels (FWPG) had even distribution of embedded oil droplets, compared to native whey protein emulsion gels. FWPG had the lowest hardness and chewiness, and exhibited better tolerance to the harden effects of NaCl on emulsion gels. FWPG can deliver curcumin more effectively during simulated gastrointestinal digestion, as evidenced by higher retention ratio and enhancement of bioaccessibility (increased by ∼ 20 %). This study provided new strategy to fabricate a homogenous emulsion gel using fibrous whey protein and to design multi-nutrient food gels for elderly.

Structural insights and aggregation propensity of a super-stable monellin mutant: A new potential building block for protein-based nanostructured materials

Protein fibrillation is commonly associated with pathologic amyloidosis. However, under appropriate conditions several proteins form fibrillar structures in vitro that can be used for biotechnological applications. MNEI and its variants, firstly designed as single chain derivatives of the sweet protein monellin, are also useful models for protein fibrillary aggregation studies. In this work, we have drawn attention to a protein dubbed Mut9, already characterized as a “super stable” MNEI variant. Comparative analysis of the respective X-ray structures revealed how the substitutions present in Mut9 eliminate several unfavorable interactions and stabilize the global structure. Molecular dynamic predictions confirmed the presence of a hydrogen-bonds network in Mut9 which increases its stability, especially at neutral pH. Thioflavin-T (ThT) binding assays and Fourier transform infrared (FTIR) spectroscopy indicated that the aggregation process occurs both at acidic and neutral pH, with and without addition of NaCl, even if with a different kinetics. Accordingly, Transmission Electron Microscopy (TEM) showed a fibrillar organization of the aggregates in all the tested conditions, albeit with some differences in the quantity and in the morphology of the fibrils. Our data underline the great potential of Mut9, which combines great stability in solution with the versatile conversion into nanostructured biomaterials.

Screening and Activity Analysis of α-Glucosidase Inhibitory Peptides Derived from Coix Seed Prolamins Using Bioinformatics and Molecular Docking.

Hydrolysates of coix seed prolamins (CHPs) have an excellent hypoglycemic effect and can effectively inhibit α-glucosidase, which is the therapeutic target enzyme for type 2 diabetes mellitus. However, its hypoglycemic components and molecular mechanisms remain unclear, and its stability in food processing needs to be explored. In this study, four potential α-glucosidase inhibitory peptides (LFPSNPLA, FPCNPLV, HLPFNPQ, LLPFYPN) were identified and screened from CHPs using LC-MS/MS and virtual screening techniques. The results of molecular docking showed that the four peptides mainly inhibited α-glucosidase activity through hydrogen bonding and hydrophobic interactions, with Pro and Leu in the peptides playing important roles. In addition, CHPs can maintain good activity under high temperatures (40~100 °C) and weakly acidic or weakly alkaline conditions (pH 6.0~8.0). The addition of glucose (at 100 °C) and NaCl increased the inhibitory activity of α-glucosidase in CHPs. The addition of metal ions significantly decreased the inhibitory activity of α-glucosidase by CHPs, and their effects varied in magnitude with Cu2+ having the largest effect followed by Zn2+, Fe3+, K+, Mg2+, and Ca2+. These results further highlight the potential of CHPs as a foodborne hypoglycemic ingredient, providing a theoretical basis for the application of CHPs in the healthy food industry.

Stability and Crystallinity of Sodium Poly(Heptazine Imide) in Photocatalysis

AbstractPoly(heptazine imide) (PHI) salts, as crystalline carbon nitrides, exhibit high photocatalytic activity and are being extensively researched, but its photochemical instability has not drawn researchers’ attention yet. Herein, sodium PHI (PHI−Na) ultrathin nanosheets with increased crystallinity, synthesized by enhancing contact of melamine with NaCl functioning as a structure‐induction agent and hard template, exhibits improved photocatalytic hydrogen evolution activity, but low photochemical stability, owing to Na+ loss in the photocatalytic process, which, interestingly, can be enhanced by the common ion effect, e.g., addition of NaCl that is also able to remarkably increase the photoactivity with the apparent quantum yield at 420 nm reaching 41.5 %. This work aims at attracting research peers’ attention to photochemical instability of PHI salts and provides a way to enhance their crystallinity.

Stability and Crystallinity of Sodium Poly(Heptazine Imide) in Photocatalysis.

Poly(heptazine imide) (PHI) salts, as crystalline carbon nitrides, exhibit high photocatalytic activity and are being extensively researched, but its photochemical instability has not drawn researchers' attention yet. Herein, sodium PHI (PHI-Na) ultrathin nanosheets with increased crystallinity, synthesized by enhancing contact of melamine with NaCl functioning as a structure-induction agent and hard template, exhibits improved photocatalytic hydrogen evolution activity, but low photochemical stability, owing to Na+ loss in the photocatalytic process, which, interestingly, can be enhanced by the common ion effect, e.g., addition of NaCl that is also able to remarkably increase the photoactivity with the apparent quantum yield at 420 nm reaching 41.5 %. This work aims at attracting research peers' attention to photochemical instability of PHI salts and provides a way to enhance their crystallinity.