A novel polyethyleneimine (PEI)-loaded Fe-doped Cu₂(OH)PO₄ adsorbent was synthesized via physical impregnation and characterized using XRD, FT-IR, SEM, XPS, and N₂ adsorption. Key parameters (Fe doping, PEI loading, temperature, flow rate) affecting CO₂ adsorption were optimized using the response surface methodology (RSM, Box–Behnken design), and flow rate was identified as the most influential factor. The optimal adsorbent, 8 %Fe–Cu₂(OH)PO₄@50 %PEI, achieved a CO₂ adsorption capacity of 3.95 mmol/g (60 °C, 30 ml/min). A significant synergistic effect (α = 3.2426) existed between Fe doping and PEI loading. RSM predictions (8.8 mol %Fe, 50.6 wt % PEI, 50.1 °C, 28 ml/min; capacity 3.95 mmol/g) closely matched those obtained in the experiment (3.90 mmol/g). The adsorbent exhibited excellent stability over 20 cycles (capacity loss: 0.35 mmol/g). Kinetic and thermodynamic studies indicated barrier-free (E_a = −41.66 kJ/mol), exothermic, spontaneous, and entropy-driven monolayer adsorption. This demonstrates that 8 %Fe–Cu₂(OH)PO₄@50 %PEI is a highly efficient and recyclable CO₂ adsorbent.

We reported on the development of mesoporous zirconium hydroxide (mp-Zr(OH)4) sorbents with high capacity for adsorptive removal of organic pollutants from industrial wastewater. The sorbent was prepared by a one-step chemical precipitation method at room temperature. The adsorption capacity and removal efficiency for the chemical oxygen demand (COD) of the industrial wastewater were studied using an automatic adsorption measurement apparatus. The effects of different parameters (adsorbent dosage, adsorption time, regeneration times, adsorbate's molecular weight and adsorbate solubility), isotherm, thermodynamics, and kinetics were evaluated. By analyzing scanning electron microscopy (SEM) images and powder X-ray diffractograms (XRD) no obvious differences were observed for the sorbents before and after the adsorption of the organics, which indicated a structural stability of the sorbent. The specific surface area was reduced from 450 m2/g to 189 m2/g on adsorption, and after desorption of the organics the specific surface area was 350 m2/g. The adsorption of COD was analyzed in a Langmuir model that described the data better than the empirical Freundlich model. This finding points towards that the adsorption occurred as a monolayer on the mp-Zr(OH)4. The free energy of adsorption (ΔG) is in the range of −20 kJ/mol < ΔG < 0. Entropy changes are ΔS > 0. The kinetics of the adsorption of COD is better described with a Quasi-second-order dynamic model than with a Quasi-first-order dynamic model, which elucidates its primary reliance on porous adsorption surfaces and incorporation of chemical adsorption.

Sn-based materials have motivated tremendous interest owing to their fascinating theoretical capacity in lithium-ion batteries. Nevertheless, the complex synthesis process and the use of toxic solvents hinder the sustainable development of Sn-based materials. Herein, we propose a simple strategy for the controllable synthesis of Sn-based materials, including Sn/SnO/mesoporous carbon (MC), Sn/SnO/SnO2/MC composites and SnO2 nanoparticles. The three-phase composites (Sn/SnO/MC) comprise dispersed Sn particles, a small amount of SnO nanosheets, and the carbonaceous matrix MC. Due to the loose binding between Sn (SnO) and carbon matrix as well as the severe agglomeration of SnO2 nanoparticles, the obtained Sn/SnO/SnO2/MC and pure SnO2 anodes display inferior electrochemical properties to Sn/SnO/MC. Specifically, the Sn/SnO/MC composite delivers a superior discharge capacity (670.3 mAh/g after 100 cycles) and impressive long-term cyclability (457.2 mAh/g after 450 cycles). In-situ XRD measurement is executed to analyze the phase evolution process of the Sn/SnO/MC anode. Moreover, the cycled full cell can lighten the “DMU” pattern composing 34 LEDs. It is significantly momentous and valuable to controllably synthesize high-performance Sn-based anode materials via a simple strategy.

A worm-like oxide Ca₃Co₂O₆ was prepared by electrostatic spinning as a cathode material for solid-oxide fuel cells. Compared to the plain granular structure, the worm-like Ca₃Co₂O₆ exhibits a desirable morphological organization and an enhanced electrochemical performance. At 1073 K, polarization resistance with the worm-like cathode is favorably reduced to 0.151 Ω cm², and the power peak of the corresponding single cell reaches to 512 mW cm⁻², showing a fast cathodic kinetics. By contrast, the polarization resistance with the plain cathode is 0.275 Ω cm², and the power peak of the corresponding single cell is 406 mW cm⁻². Under a constant voltage load of applied 0.6 V at 1023 K, cell power with the worm-like cathode maintains steadily from 420 to 400 mW cm⁻² after 14 h of running time, showing a less fading rate, a more stable performance, and a better application prospect than the plain cathode.

Silver nanoparticles (AgNPs) with different sizes have been extensively adopted in various commercial products, causing ecological concerns because of the inevitable release of AgNPs into the environment. Hence, understanding the interaction of different-sized AgNPs with environmental substances is important for assessing the environmental risk and fate of AgNPs. In this work, we investigated the impact of anions (NO3−, SO42−, HCO3−/CO32−, Cl−) in aquatic environments on the physicochemical properties and antibacterial activity of different-sized AgNPs (20, 40 and 57 nm). The results showed that the anions whose corresponding silver-based products had lower solubility were more likely to decrease the zeta potential (more negative) of particles, inhibit the dissolution of AgNPs and reduce their antibacterial activity. This should be attributed to the easier generation of coating layers on the surface of AgNPs during the incubation process with such anions. Additionally, the generation of coating layers was also found to be particle-size dependent. The anions were more prone to adsorbing onto larger-sized AgNPs, promoting the formation of coating layers, subsequently resulting in more pronounced variations in the physicochemical properties and antibacterial activity of the larger-sized AgNPs. Therefore, larger-sized AgNPs were more prone to experiencing specific effects from the anions.

Global warming, primarily driven by emissions of greenhouse gases, particularly carbon dioxide, has emerged as a widely acknowledged concern. Hence, the development of novel carbon capture materials with high capacity and low cost holds substantial practical significance. This study investigates the influence of aging time, pH, and copper salt on the synthesis of Cu2(OH)PO4 and its CO2 adsorption performance. Cu2(OH)PO4 adsorbents were synthesized under various aging time, pH, and copper salt conditions, and their morphology and surface functional groups were characterized. Experimental findings indicate that excessively prolonged or abbreviated aging times adversely affect the formation of distinct, discernible lamellar structures within the material. Different pH levels influence the stacking configuration of the lamellae, impacting both their thickness and size. Under acidic conditions, lamellae exhibit dispersed three-dimensional stacking; under neutral conditions, lamellae notably enlarge and demonstrate two-dimensional stacking; at pH 9, lamellae stack three-dimensionally and aggregate. Additionally, the CO2 adsorption performance of Cu2(OH)PO4 adsorbents synthesized with different copper salts varies. By examining the relationship between surface functional group content and CO2 adsorption capacity, we deduced the mechanism by which various synthesis conditions affect both surface functional groups and adsorption capacity. Cu2(OH)PO4 synthesized with a 24 h aging time, pH 7, and CuSO4 as the copper salt exhibits the highest CO2 adsorption capacity, achieving 1.006 mmol/g.

Infectious diseases caused by waterborne viruses have attracted researchers’ great attention. To ensure a safe water environment, it is important to advance water treatment and disinfection technology. Photocatalytic technology offers an efficient and practical approach for achieving this goal. This paper reviews the latest studies on visible-light composite catalysts for bacteriophage inactivation, with a main focus on three distinct categories: modified UV materials, direct visible-light materials and carbon-based materials. This review gives an insight into the progress in photocatalytic material development and offers a promising solution for bacteriophage inactivation.

This study focused on creating tetraethylenepentamine (TEPA) modified copper hydroxyl phosphate (Cu2(OH)PO4) adsorbents via physical impregnation. The TEPA-modified Cu2(OH)PO4 adsorbents were analyzed for structure and characteristics through SEM, XPS, TGA, N2 adsorption–desorption studies. The effects of different parameters (TEPA contents, temperatures, flow rates and CO2 concentrations) and cyclic stability were evaluated. Kinetics, thermodynamics and density functional theory (DFT) calculations were employed to understand the impact of TEPA modification on Cu2(OH)PO4 for CO2 adsorption. Experimental results showed that a 50 wt% loading yielded optimal results, with a maximum surface area of 65.12 m2/g, a pore volume of 0.29 cm3/g, and a maximum adsorption capacity of 6.54 mmol/g. The amine efficiency is extraordinary which reached 67 %. The best performance occurred at 60 °C, 30 ml/min gas flow, and 15 vol% CO2 concentration. The pseudo-second-order kinetic model better described the CO2 adsorption process. The adsorption process was found to be exothermic at 20–60 °C and endothermic at 60–80 °C, suggesting physical–chemical co-adsorption and chemical adsorption, respectively. The adsorption activation energy is 34.322 kJ/mol. The DFT shows the adsorption energy ranged from −0.565 eV to −5.584 eV, indicating coexistence of physical and chemical adsorption. The d-band theoretical calculation shows that TEPA doping is beneficial to the adsorption of CO2 by Cu2(OH)PO4. Minimal structural modification of the adsorbate was observed, with bond lengths changing by less than 1 %. The density of states (DOS) curve shifted toward lower-energy states after adsorption, suggesting a more stable structural configuration post-adsorption. We have proved that TEPA-Cu2(OH)PO4 has good adsorption for CO2 and is an efficient green adsorption material.

We hypothesized that photocatalysts with a low band gap could be useful in the sterilization of ceramic tiles in the natural environments of toilets using natural light in those settings. Certain photocatalysts can produce reactive oxygen species (ROS) under light illumination, which in turn are bactericidal. The properties of the BiOBr-containing photocatalysts were tuned by creating junctions and heterostructures with Ag and InVO₄ and studied with respect to their bactericidal effect in dispersion. The bactericidal mechanism was studied through experiments in which active species were captured and via electron paramagnetic resonance (EPR) spectroscopy. At an optimal dosage of 0.5 g/L, the Ag/InVO₄/BiOBr composite had a sterilization efficacy of 99.9999 % in 30 min under visible light illumination of 1000 W. It retained a sterilization efficacy of 99.999 % after four cycles. Anions such as Cl⁻, SO₄²⁻, and NO₃⁻ were shown to have no negative impact on sterilization efficacy. It was shown that the holes in the composite photocatalyst and hydroxyl radicals (·OH) were mechanistically critical for the sterilization. The photocatalysts were also studied in the field in the natural environment of a restroom, where they were loaded on ceramic tiles. Samples were collected from the surface of the ceramic tiles and analyzed for bacterial cultures and microbial diversity. The results were compared in the scope of the sterilization ability of various agents at the microbial level. The ceramic tiles loaded with Ag/InVO₄/BiOBr showed the least amount of bacteria on their surfaces, and the microbial community richness was also the lowest.

Metal doping plays a momentous role in heightening the electronic conductivity of Sn₄P₃. This work proposes the facile synthesis of Fe-doped Sn₄P₃ via a solid-state reaction process. The resulting Fe-doped Sn₄P₃ is stacked by a great quantity of nanoparticles. As the ionic radius of Fe³⁺ (64.5 p.m.) is slightly smaller than that of Sn⁴⁺ (69 p.m.), Fe³⁺can easily dope into the structure of Sn₄P₃. The Sn₄P₃ anode with 5% Fe doping delivers a larger initial discharge capacity of 1105.1 mAh/g and coloumbic efficiency of 86.2%. After 200 cycles, a high discharge capacity of 972.4 mAh/g is reached, while the discharge capacity of un-doped Sn₄P₃ anode merely maintains at about 423.3 mAh/g. As an inactive matrix, Fe atoms can disperse among Sn atoms, thus inhibiting the aggregation of Sn atoms during cycling. The results display that Fe doping in Sn₄P₃ structure is extremely vital to heighten the architecture stability and electrochemical performance. This facile solid-state reaction process can be enlarged to the manufacture of other metal-doped Sn₄P₃ in the field of lithium-ion batteries.