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•CoM/TNTs showed high ACE degradation efficiency after PMS activation.•Efficient PMS activation was due to the synergic effect of Co(OH)2 and TNTs.•TNTs with abundant surface –OH ...facilitated formation of CoOH+.•PES analysis well explained the higher feasibility of Co(OH)+ on PMS activation.•ACE atoms with high Fukui index are active sites for electrophilic attack.
Pharmaceuticals and personal care products (PPCPs) are of great concern due to their increasing health effects, so advanced treatment technologies for PPCPs removal are urgently needed. In this study, titanate nanotubes decorated Co(OH)2 hollow microsphere (CoM/TNTs) composites were synthesized by a two-step solvothermal method, and used to activate peroxymonosulfate (PMS) through heterogenous catalysis for acetaminophen (ACE) degradation in water. The optimum material (CoM/TNTs0.5) activated PMS system exhibited high ACE removal efficiency and quick kinetic, as 93.0% ACE was degraded even within 10 min. The two components in CoM/TNTs showed a synergetic effect on PMS activation for radicals production: Co(OH)+ from CoM was the primary active species to active PMS, while TNTs could offer abundant –OH groups for Co(OH)+ formation. Density functional theory (DFT) calculation further interpreted the mechanism of Co(OH)+ for PMS activation by means of reaction potential energy surface (PES) analysis. Both the scavenger quenching tests and electron paramagnetic resonance analysis revealed that the sulfate radical (SO4-·) played a dominant role in ACE degradation. Moreover, DFT calculation also suggested that the ACE atoms with high Fukui index (f-) represented the active sites for electrophilic attack by SO4-·. The toxicity analysis based on quantitative structure-activity relationship (QSAR) verified the reduced toxicity of transformation products. Furthermore, CoM/TNTs also had good reusability and stability over five cycles. This work provides deep insights into the reaction mechanisms of radical production and organics attack in cobalt-based PMS activation system.
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•We proposed a series of transition metal borides (MBenes) monolayer as NRR catalysts.•MBenes exhibit metallic features and electrene characteristics for NRR activity.•Work function ...of the MBenes can be adopted as a descriptor for the NRR activity.
Low-energy consumption and highly selective nitrogen reduction reaction (NRR) catalysts play an important role in solving the limitations of the traditional ammonia production. By means of first-principle calculations, we proposed a series of two-dimensional (2D) transition metal borides (MB) (M = Sc, Ti, V, Y, Zr, Nb, Mo, Hf, Ta and W) monolayer as NRR catalysts. These 2D MBenes exhibit high stability, metallic electronic band structures and the electrene characteristics which contribute to the NRR catalytic activity. Large amounts of active sites accelerate the NRR reaction, and the high selectivity towards NRR inhibits the HER process. We screened out four MBenes: TiB, YB, ZrB and MoB, with favorable limiting overpotentials of 0.64, 0.68, 0.65 and 0.68 V, respectively, which are promising for N2 fixation applications. This work not only enriches the MBene family, but also provides a feasible strategy for the design of NRR catalysts.
The g-C3N4/TiO2 nanocomposites (NCs) are fabricated by optimization of calcination and subsequent hydrothermal technique decorated with CeO2 nanoparticles (NPs) to build the g-C3N4/TiO2–CeO2 hybrid ...NCs. The chemical and surface characterizations of structural, morphological, elemental composition, optical, photo-degradation, HER performance and the DFT computation has been efficiently analyzed. The g-C3N4/TiO2–CeO2 composite photocatalysts (PCs) exhibit photocatalytic improved performance (∼97 %) for MB aqueous dye related to pristine g-C3N4 and g-C3N4/TiO2 composite PCs. The obtained k value of the g-C3N4/TiO2/CeO2 heterostructure composite PCs has around 0.0262 min−1 and 6.1, 2.6 and 1.5 times higher than to g-C3N4 (0.0043 min−1), g-C3N4/CeO2 (0.0099 min−1) and g-C3N4/TiO2 (0.0180 min−1) PCs respectively. Likewise, the synergistic probable S-scheme charge separation mechanism based on scavengers’ tests and other values, which leads to effective separation of photo-excited (e−-h+) pairs, whereas high degradation and more H2O molecules have photo-reduction to H2. The H2 evolution reaction (HER) and the electrochemical impedance spectroscopy (EIS) of the as-obtained samples were explored via electrochemical study. This exertion recommends that the rational strategy and building of g-C3N4/TiO2–CeO2 nano-heterostructures were beneficial for developing visible-light-driven recyclable PCs for ecological refinement.
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•CeO2 coupled g-C3N4/TiO2 photocatalyst was effectively prepared by a facile method.•Optimum degradation efficiency was 6.1 times higher than g-C3N4 under visible-light.•XPS and DFT study ensues a strong interface among Ti, Ce and O atoms into g-C3N4.•g-C3N4/TiO2/CeO2 S-scheme heterostructure exposed superior H2 production activity.•Also, good reusability for organic dye degradation and efficient HER performance.
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•The natural chalcopyrite can efficiently activate PMS to degrade bisphenol S.•The main free radicals responsible for BPS degradation at different initial pH were studied.•The role of ...copper, iron and sulfur species were investigated.•Bisphenol S degradation mechanism in NCP/PMS system was proposed by DFT calculation.
In this study, natural chalcopyrite (NCP) was employed in the activation of peroxymonosulfate (PMS) for bisphenol S (BPS) degradation. Firstly, the NCP catalyst was characterized via X-ray diffraction (XRD), scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) techniques. Then, several key parameters such as catalyst dosage, PMS dosage and initial pH were investigated in NCP/PMS system. Furthermore, the transformation of various free radicals (SO4•−, •OH and O2•−) with the changes of initial pH were investigated by quenching experiments and electron spin resonance (ESR) study. Also, sulfur species cycling of copper and iron species were investigated via exogenous Cu2+ and Fe3+ addition experiments and X-ray photoelectron spectroscopy (XPS) analysis, the result indicated that sulfur species promoted Fe3+/Fe2+ and Cu2+/Cu+ cycles on the NCP surface. Furthermore, thirteen major degradation intermediates of BPS were detected by UPLC-QTOF-MS/MS and density functional theory (DFT) method was used to illustrate possible reaction pathways of BPS. Finally, a reasonable reaction mechanism of NCP/PMS system for BPS degradation was proposed on the basis of the comprehensive analysis. In brief, this work helps to provide useful information for the application of natural metallic sulfide minerals in treatment of contaminated waters.
The consequences of antibiotic misuse, leading to the proliferation of drug-resistant bacteria, present a significant challenge to the field of medicine. Natural compounds such as epigallocatechin ...gallate (EGCG), derived from green tea, exhibit potent anti-tumor and antibacterial properties. However, the adaptability of tumors to chemotherapy due to their acidic pH and elevated levels of glutathione (GSH), coupled with the challenges posed by postoperative drug-resistant bacterial infections, hinders treatment outcomes. This study successfully synthesized a self-assembling nanocomposite, Cu-EGCG. Leveraging chemodynamic therapy (CDT), photothermal therapy (PTT), and photodynamic therapy (PDT), Cu-EGCG demonstrated robust anti-tumor and antibacterial effects. Additionally, Cu-EGCG exhibited excellent photothermal conversion under 808 nm near-infrared (NIR) radiation, generating singlet oxygen (1O2) upon laser irradiation. In murine tumor and wound models, Cu-EGCG consistently displayed significant anti-tumor and antibacterial efficacy.
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Chemotherapy and surgery stand as primary cancer treatments, yet the unique traits of the tumor microenvironment hinder their effectiveness. The natural compound epigallocatechin gallate (EGCG) possesses potent anti-tumor and antibacterial traits. However, the tumor’s adaptability to chemotherapy due to its acidic pH and elevated glutathione (GSH) levels, coupled with the challenges posed by drug-resistant bacterial infections post-surgery, impede treatment outcomes. To address these challenges, researchers strive to explore innovative treatment strategies, such as multimodal combination therapy. This study successfully synthesized Cu-EGCG, a metal-polyphenol network, and detailly characterized it by using synchrotron radiation and high-resolution mass spectrometry (HRMS). Through chemodynamic therapy (CDT), photothermal therapy (PTT), and photodynamic therapy (PDT), Cu-EGCG showed robust antitumor and antibacterial effects. Cu+ in Cu-EGCG actively participates in a Fenton-like reaction, generating hydroxyl radicals (·OH) upon exposure to hydrogen peroxide (H2O2) and converting to Cu2+. This Cu2+ interacts with GSH, weakening the oxidative stress response of bacteria and tumor cells. Density functional theory (DFT) calculations verified Cu-EGCG’s efficient GSH consumption during its reaction with GSH. Additionally, Cu-EGCG exhibited outstanding photothermal conversion when exposed to 808 nm near-infrared (NIR) radiation and produced singlet oxygen (1O2) upon laser irradiation. In both mouse tumor and wound models, Cu-EGCG showcased remarkable antitumor and antibacterial properties.
In this study, a “cage” strategy was developed to effectively control the dissolution of Ca2+ into water without losing F− removal rate. Specifically, calcium oxide loaded with zinc‑aluminum ...composite oxides was synthesized as an adsorbent using urea hydrothermal method and a high temperature calcination process with limescale waste as the precursor, which achieved high efficiency in removing fluoride (qe = 336.41 mg·g−1) while inhibiting the dissolution of Ca2+ (cCa2+=98.34 mg·L−1) in the adsorbent due to the encapsulation of calcium oxide by zinc‑aluminum oxide particles agglomerates and thus reducing the secondary pollution generated by the adsorbent. The results of batch adsorption experiments show that the adsorbent has better adsorption performance than most fluoride adsorbents and can be applied in a wide pH range (3–11) and has strong resistance to the effect of coexisting anions. The precipitate of calcium fluoride, ion exchange, electrostatic interactions and hydrogen bonding are the main adsorption mechanisms. The results of the study suggest that the calcium oxide loaded by zinc‑aluminum composite oxides synthesized from inexpensive limescale waste as precursor provides a new idea for the development of low-cost and high-efficiency fluoride adsorbents, as well as solves the problem of secondary contamination of traditional calcium-based adsorbents.
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•A CaO loaded with ZnAl composite oxides is prepared with limescale as precursor.•The F− adsorption capacity of the adsorbent was higher than that of most adsorbents.•The modification of CaO by ZnAl effectively inhibited the dissolution of Ca2+.•The reuse of limescale reduces the environmental hazards of its waste.•The reuse of cheap and readily available limescale reduces the cost.
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•CQDs/TiO2/WO3 is designed on the basis of dual alignment and charge distribution.•TiO2 epitaxially grow on WO3 with ~3% lattice mismatch to form heterojunction.•The built-in field of ...TiO2/WO3 can inhibit bulk recombination with band alignment.•CQDs can extend visible light absorption and shift onset potential cathodically.•PEC water splitting performance of CQDs/TiO2/WO3 has been significantly improved.
Photoanode is the key issue for photoelectrocatalytic (PEC) water splitting and organics degradation. However, it always faces several restrictions including severe photocorrosion, low charge separation and transfer efficiencies, poor visible light harvesting, and sluggish interfacial reaction kinetics, which often required a variety of modifications with only low improvements achieved. Herein, a high performance CQDs/TiO2/WO3 photoanode was designed on the basis of density function theory (DFT) alignment of lattice parameters and energy band, and charge distribution. The TiO2/WO3 heterojunction can abate photocorrosion through the hetero-epitaxial growth of TiO2 (001) on WO3 (002) for the lattice mismatch <3% eliminating dangling bonds, with high corrosion resistance and photostability of TiO2. As the built-in field constructed by a staggered band alignment structure with the valence band offset (VBO) of 0.51 eV, the photogenerated carriers transfer and separation are promoted dramatically. Through the DFT calculations, the sunlight absorption wavelength can be extended, and the interfacial reaction kinetics can be expedited with the modification of carbon quantum dots (CQDs) on TiO2/WO3, due to the narrower bandgap (Eg) and the accumulation of electrons at TiO2 side. The DFT designed CQDs/TiO2/WO3 photoanode significantly increase photocurrent density from 0.90 to 2.03 mA cm−2 at 1.23 V, charge separation efficiency from 56.3 to 79.2% and charge injection efficiency from 51.2 to 70.4%, and extend light absorption edge from 455 to 463 nm over pristine WO3, with better photostability and lower holes-to-water resistance.
In this study, the oxidation of 1-naphthol (1-NAP) and 2-naphthol (2-NAP) by Fe(VI) was investigated. The impacts of operating factors were investigated through a series of kinetic experiments, ...including Fe(VI) dosages, pH and coexisting ions (Ca2+, Mg2+, Cu2+, Fe3+, Cl−, SO42−, NO3− and CO32−). Almost 100% elimination of both 1-NAP and 2-NAP could be achieved within 300 s at pH 9.0 and 25 °C. Cu2+ could significantly improve the degradation efficiency of 1-NAP and 2-NAP, but the impacts of other ions were negligible. The liquid chromatography-mass spectrometry was used to identify the transformation products of 1-NAP and 2-NAP in Fe(VI) system, and the degradation pathways were proposed accordingly. Electron transfer mediated polymerization reaction was the dominant transformation pathway in the elimination of NAP by Fe(VI) oxidation. After 300 s of oxidation, heptamers and hexamers were found as the final coupling products during the removal of 1-NAP and 2-NAP, respectively. Theoretical calculations demonstrated that the hydrogen abstraction and electron transfer reaction would easily occur at the hydroxyl groups of 1-NAP and 2-NAP, producing NAP phenoxy radicals for subsequent coupling reaction. Moreover, since the electron transfer reactions between Fe(VI) and NAP molecules were barrierless and could occur spontaneously, the theoretical calculation results also confirmed the priority of coupling reaction in Fe(VI) system. This work indicated that the Fe(VI) oxidation was an effective way for removing naphthol, which may help us understand the reaction mechanism between phenolic compounds with Fe(VI).
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•The oxidative removal of 1-NAP and 2-NAP by Fe(VI) was compared.•The transformation pathways of 1-NAP and 2-NAP were proposed.•Electron transfer-mediated polymerization was considered as the dominant pathway.•DFT calculated was conducted to prove the rationality of the reaction mechanisms.
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•A thiophene was successfully introduced to a reticulated polyamide with tri(4-aminophenyl)benzene.•The polyamide containing thiophene and tri(4-aminophenyl)benzene exhibits high ...selectivity and reproducibility for Hg2+.•Spectroscopic techniques and DFT calculations revealed the main adsorption mechanism of TPPA on Hg2+.
In this study, the thiophenyl polyamide (TPPA) derived from tri(4-aminophenyl) benzene was synthesized for the removal of Hg2+ from the aqueous solution. The adsorbent was characterized by the Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, nitrogen adsorption–desorption, thermogravimetric analysis and differential scanning calorimetry. The adsorption capacity of Hg2+ is 518.7 mg g−1 at a dose of 1.1 g/L of adsorbent. TPPA was shown to have the following advantages: (i) the high selectivity for the excess metal ions Hg2+, (ii) the stability in the pH values ranging between 2 and 6, and (iii) the proper recyclability (87 % of Hg2+ can be removed in 5 adsorption–desorption cycles). Our analysis suggests the models of the pseudo-second-order kinetics and the Langmuir isotherm are suitable for the description of the adsorption of Hg2+ on the thiophene network polyamide. Our experimental and theoretical results reveal the relationship between the structures and the adsorption capacities of TPPA, identifying the oxygen atom (amide) and the sulphur atom (thiophene) as the most important chemical-reaction sites.
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The severe hazards on ecological environment and human body caused by volatile organic compounds (VOCs) have attracted worldwide substantial attention. In this research, a series of ...novel modified Universitetet i Oslo-67 (UiO-67) with water resistance were prepared and characterized, which had modified by benzoic acid and dopamine hydrochloride (67-ben-DH). On this basis, the adsorption performance, adsorption kinetics, defect engineering and water resistance of adsorbent were investigated. The results indicated that the excellent pore structure and specific surface area of 67-ben-DH-6 (molar ratio of Zr4+ to DH was 1:6) were retained while the adsorption performance and water resistance of the adsorbent were improved. Due to more defects, excellent adsorption diffusion and strong π-π interactions of 67-ben-DH-6, it performed the maximum adsorption capacity of toluene (793 mg g−1). Furthermore, the outstanding water resistance was attributed to the fact that N element of DH reduced the affinity of the adsorbent with water. Finally, the density functional theory (DFT) calculations showed that the adsorbent 67-ben-DH-6 had the maximum adsorption energy for toluene (-99.4 kJ mol−1) and the minimum adsorption energy for water (-17.8 kJ mol−1). Thus, the potential mechanism of 67-ben-DH for efficient toluene adsorption and water resistance was verified from a microscopic perspective.
