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The development of facile and efficient synthetic approaches of carbon quantum dots loaded with mesoporous g-C3N4 (mpg-C3N4/CQDs) is of critical urgency. Here, a facile strategy was developed to synthesize the mpg-C3N4/CQDs by using calcinations of the mixture of CQDs, cyanamide, and silica colloid. The obtained composite still retained a considerable total surface area, which could offer a larger population of adsorption sites; therefore enhance the capacity for the adsorption of fluoroquinolones antibiotics (FQs). Under visible light irradiation, mpg-C3N4/CQDs demonstrated a higher photocatalytic activity for FQs degradation than did bulk g-C3N4 or mpg-C3N4. This enhancement might have been ascribed to the high surface area of the mpg-C3N4, unique up-converted photoluminescence (PL) properties, and the efficient charge separation of the CQDs. The eradication of FQs followed the Langmuir–Hinshelwood (L–H) kinetic degradation model and absorption pseudo-second-order kinetic model, indicating that surface reactions and chemical sorption played significant roles during the photocatalysis process. The results of electron spin resonance (ESR) technology and reactive species (RSs) scavenging experiments revealed that the superoxide anion radical (O2Ṗ−) and photo-hole (h+) were the primarily active species that initiated the degradation of FQs. Based on the identification of intermediates and the prediction of reactive sites, the degradation pathways of ofloxacin (OFX) were proposed. A residual antibiotic activity experiment revealed that mpg-C3N4/CQDs provided very desirable performance for the reduction of antibiotic activity. [ABSTRACT FROM AUTHOR]

Objectives: Teicoplanin, an antibiotic, has poor clinical efficacy when using the current drug label's recommended regimen, which is approved by the China Food and Drug Administration. This study explores the appropriate loading and maintenance doses of teicoplanin and evaluates the therapeutic target of teicoplanin trough concentration (minimum concentration [Cmin]). Subjects and methods: All patients treated with teicoplanin from February 2015 to August 2016 at Zhengzhou Central Hospital were screened for enrollment. A total of 113 subjects were included and then divided into four groups: A (received three to six doses at a loading dose of 400 mg at 12-hour intervals, followed by maintenance dosing of 400 mg/day), B (received three doses at a loading dose of 400 mg at 12-hour intervals, followed by maintenance dosing of 400 mg/day), C (received two doses at a loading dose of 400 mg at 12-hour intervals, followed by maintenance dosing of 200 mg/day), and D (received one to three doses at a loading dose of 400 mg at 12-hour intervals, followed by maintenance dosing of 200 mg/day). Cmin values of teicoplanin were detected with high-performance liquid chromatography on day 4, 30 minutes before maintenance-dose administration. Teicoplanin Cmin, efficacy, and safety were compared among the four groups. Results: Mean Cmin differed significantly among the four groups (A, 18.11±6.37 mg/L; B, 15.91±4.94 mg/L; C, 17.06±5.66 mg/L; D, 11.97±3.76 mg/L) (P<0.001), with creatinine clearance of 89.62 (53.72-162.48), 49.66 (40.69-59.64), 27.17 (9.7-39.45), and 96.6 (17.63-394.73) mL/min, respectively. The ratio of loading dose for 3 days to creatinine clearance and serum Cmin were significantly correlated (R=0.59, P<0.001). The correlation between the estimated probability of success and teicoplanin Cmin was assessed using binary logistic regression (OR 2.049, P<0.001). Hepatotoxicity- and nephrotoxicity-incidence rates did not significantly differ among the four groups (P=0.859 and P=0.949, respectively). Conclusion: A loading dose of 400 mg at 12-hour intervals three to six times is needed to achieve the early target range (15-20 mg/L) and improve the clinical efficacy rate for normalrenal- function patients. It is urgently necessary to amend the drug label for the recommended regimen. [ABSTRACT FROM AUTHOR]

Humin is the component of humic substances that is recalcitrant to extraction by either strong bases or strong acids, which contains a variety of functional groups that may combine with heavy metal ions. The present study employed humin as an adsorbent to investigate the efficacy of a remediation strategy under the effects of humin-enhanced electrokinetics. Because the cations gravitate toward cathode and anions are transferred to anode, humin was placed in close proximity to the cathode in the form of a package. The humin was taken out after the experiments to determine whether a target pollutant (cadmium) might be completely removed from soil. Acetic acid-sodium acetate was selected as the electrolyte for these experiments, which was circulated between the two electrode chambers via a peristaltic pump, in order to control the pH of the soil. The results indicated that when the remediation duration was extended to 240 h, the removal of acid extractable Cd(II) could be up to 43.86% efficiency, and the adsorption of the heavy metal within the humin was 86.15 mg/kg. Further, the recycling of the electrolyte exhibited a good control of the pH of the soil. When comparing the pH of the soil with the circulating electrolyte during remediation, in contrast to when it was not being recycled, the pH of the soil at the anode increased from 3.89 to 5.63, whereas the soil at the cathode decreased from 8.06 to 7.10. This indicated that the electrolyte recycling had the capacity to stabilize the pH of the soil. [ABSTRACT FROM AUTHOR]

The novel leaf-like TFP-Dg Cl is a cationic covalent organic framework with a specific structure. It can selectively adsorb non-steroidal anti-inflammatory drugs (NSAIDs) from pharmaceutical and personal care products (PPCPs)-contaminated wastewater, showing excellent performance for the removal of NSAIDs. [Display omitted] In recent years, ionic covalent organic frameworks (iCOFs) have become popular for the removal of contaminants from water. Herein, we employed 2-hydroxybenzene-1,3,5-tricarbaldehyde (TFP) and 1,3-diaminoguanidine monohydrochloride (Dg Cl) to develop a novel leaf-like iCOF (TFP-Dg Cl) for the highly efficient and selective removal of non-steroidal anti-inflammatory drugs (NSAIDs). The uniformly distributed adsorption sites, suitable pore sizes, and functional groups (hydroxyl groups, guanidinium groups, and aromatic groups) of the TFP-Dg Cl endowed it with powerful and selective adsorption capacities for NSAIDs. Remarkably, the optimal leaf-like TFP-Dg Cl demonstrated an excellent maximum adsorption capacity (1100.08 mg/g) for diclofenac sodium (DCF), to the best of our knowledge, the largest adsorption capacity ever achieved for DCF. Further testing under varying environmental conditions such as pH, different types of anions, and multi-component systems confirmed the practical suitability of the TFP-Dg Cl. Moreover, the prepared TFP-Dg Cl exhibited exceptional reusability and stability through six adsorption–desorption cycles. Finally, the adsorption mechanisms of NSAIDs on leaf-like TFP-Dg Cl were confirmed as electrostatic interactions, hydrogen bonding, and π-π interactions. This work significantly supplements to our understanding of iCOFs and provides new insights into the removal of NSAIDs from wastewater. [ABSTRACT FROM AUTHOR]

• Fe-ONLH/PMS showed superiority in applicability, stability and environmental safety. • 1O 2 generated from activated PMS dominated the degradation of CQP. • Interactions between Fe-ONLH and PMS adsorbed on active sites were unveiled via DFT calculation. • Possible decomposition pathways and toxicity trends of CQP in Fe-ONLH/PMS were proposed. The utilization of peroxymonosulfate (PMS)-based advanced oxidation process as a proficient approach for treating wastewater has garnered significant attention. However, the activation of PMS and the degradation of contaminants are highly dependent on or severely limited by the design and structured active sites of catalysts. Herein, an Fe-based O-doped polymeric carbon nitride catalyst, namely Fe-ONLH, was synthesized to activate PMS for the efficient removal of model pollutant chloroquine phosphate (CQP) via a non-radical dominant pathway with singlet oxygen (1O 2). The rapid degradation of CQP in the developed Fe-ONLH/PMS system was achieved by the optimum degradation conditions predicted by Response Surface Method (RSM) and the catalyst dosage was considered to have the highest relative importance among the variables. Particularly, the ability of Fe and oxygen co-dopants to generate non-radical active species is mainly attributed to the various active sites on Fe-ONLH (e.g., Fe-O, graphite N, C O and N C-N 2), which also exhibited advantages in adaptability of wide pH range, catalyst reusability, stability in complicated ionic environmental or water matrixes. Besides, probable intermediates and decomposition pathways of CQP attacked by non-radicals and radicals were analyzed. The current study provides new insights of Fe-base heterogeneous catalysts for PMS activation and non-radical pathway degradation of pollutants during wastewater treatment. [ABSTRACT FROM AUTHOR]

Advanced oxidation processes are a desirable technology for treatment of contaminants of emerging concern. Nevertheless, conventional advanced oxidation of organophosphorus compounds releases inorganic phosphate, posing downstream concerns related to eutrophication. For this reason, we evaluated the ultraviolet light-activated calcium peroxide (UV/CaO 2) system for effective treatment of organophosphorus compounds and concurrent capture of the mineralization products, phosphate. The degradation mechanisms, reaction kinetics, and mineralizations were assessed to determine the overall efficiency and performance of the UV/CaO 2 process. Knowledge gaps related to photocatalysis in the UV/CaO 2 system were not only addressed, but also leveraged to identify unique advantages for removal of organophosphorus compounds and their degradation products. Experimental results confirmed that the UV/CaO 2 system effectively mineralized organophosphorus compounds and recovered inorganic phosphate; additionally, collaborative carbon fixation performance of the system reveals the potential of carbon utilization. These outcomes were facilitated by the alkaline environment generated by CaO 2. The recovered solids contained most of the phosphorus and carbon from the parent compounds. Ultimately, these findings provide transformative, new insights into the development and application of advanced oxidation processes that prevent downstream concerns related to mineralization products, especially inorganic phosphorus and carbon. [Display omitted] • The UV/CaO 2 system degraded organophosphorus compounds without releasing byproducts. • Phosphate and carbon dioxide produced by mineralization reactions were captured. • Organophosphorus degradation mechanisms included photolysis and photocatalysis. • Photocatalytic mechanisms and byproduct capture were enhanced in alkaline solution. • Phosphorus and carbon were recovered as valuable products with downstream value. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe-CGB/PMS was 47 times higher than spent coffee grounds in removing chloroquine phosphate. • SO 4 ·− and ·OH generated from activated peroxymonosulfate dominated the degradation of chloroquine phosphate. • Fe-CGB/PMS can totally eliminate chloroquine phosphate in extreme pH and different water environments. • Fe-CGB/PMS showed applicability in removing different types of pollutants. Iron-doped biochar catalyst (Fe-CGB) was synthesized by embedding rust into coffee grounds using a high-temperature water bath. Fe-CGB was then used with activated peroxymonosulfate (PMS) to treat chloroquine phosphate (CQP) contaminated wastewater. The presence of biochar facilitates the cycling between Fe(III) and Fe(II) species, thereby augmenting the activation efficacy of PMS. The Fe-CGB/PMS system demonstrated exceptional catalytic degradation efficacy, achieving complete removal of CQP within a mere 30 min, with a reaction rate constant of 0.1501 min−1, surpassing the unmodified coffee grounds biochar by a factor of 47. Notably, under extreme pH conditions and in the presence of complex inorganic ions, CQP was entirely eliminated within 60 min. Mechanistic investigations revealed that biochar-mediated promotion of the Fe(III)/Fe(II) cycle amplifies the activation efficiency of PMS, leading to the generation of abundant sulfate radicals (SO 4 ·−) and hydroxyl radicals (·OH), which facilitate pollutant decomposition. Furthermore, Fe-CGB exhibited notable stability across multiple cycles, with minimal iron ion leaching and facile separation from the solution. Subsequently, the degradation effects of 18 organic pollutants were evaluated, and their potential as effective treatment methods for multiple pollution scenarios were explored in combination with theoretical calculations. Overall,this study provides insights into PMS activation as well as waste management. [ABSTRACT FROM AUTHOR]

[Display omitted] • Significantly enhances exciton dissociation and facilitates carrier transfer. • Featuring abundant oxygen vacancies and achieving notable O 2 activation efficiency. • Demonstrates outstanding photocatalytic activity under low-power blue LED. • Detailed photocatalytic mechanisms and degradation pathways were proposed. The strong excitonic effect significantly influences the efficiency of electron-hole pair generation. Therefore, promoting the dissociation of excitons into free charge carriers has drawn much attention. In this study, nitrogen (N)-doped BiOBr photocatalyst (BOBNC) modified with carbon quantum dots (CQDs) was synthesized via a solvothermal method. We demonstrated through photoluminescence and photoelectrochemical techniques the synergistic effect of oxygen vacancies and CQDs, facilitating exciton dissociation and charge carrier migration, consequently significantly enhancing the electron density in the material. Compared to pure BiOBr, degradation experiments revealed that the optimized doping ratio of 0.5BOBNC with CQDs increased the rate constant for sulfamethoxazole (SIZ) by 19.89 times. Furthermore, based on quenching experiments, electron spin resonance (ESR) tests, and DFT calculations, h+, O 2 •− and 1O 2 were identified as the primary reactive species for SIZ degradation, and a photocatalytic mechanism was proposed. Additionally, the influence of various environmental factors on the photocatalytic system was investigated. In conclusion, this work not only contributes to a profound understanding of BiOBr exciton dissociation but also presents a promising photocatalytic technique for the remediation of diverse water environments. [ABSTRACT FROM AUTHOR]

[Display omitted] • Magnetic ionic covalent organic framework M–TDiCOF was synthesized by a facile method. • M–TDiCOF exhibited a high adsorption capacity and fast removal. • M–TDiCOF demonstrated an excellent maximum adsorption capacity of 371.27 mg/g for DCF. • The prepared M–TDiCOF was reliable, stable, and easily recoverable. • The adsorption mechanism of M–TDiCOF was attributed to electrostatic interactions, H-bond, π-π interactions, and ion exchange. Ionic covalent organic frameworks (iCOFs) have shown promise in non-steroidal anti-inflammatory drugs (NSAIDs) removal, but their recycling from solutions remains challenging. In this study, the development of a novel magnetic iCOF (M–TDiCOF) based on Schiff base reaction using amino functional group modified NH 2 -Fe 3 O 4 as a magnetic source was reported. The resulting M–TDiCOF exhibits high adsorption capacity and fast kinetics, and can be easily separated and regenerated. Notably, M–TDiCOF achieves equilibrium adsorption of diclofenac sodium (DCF) within 30 min and shows a higher adsorption capacity under acidic conditions (371.27 mg/g, pH = 5). Kinetics and isotherms studies expose the adsorption of M–TDiCOF for DCF following the pseudo second-order kinetic model and Langmuir isotherm model. The correlation between the physicochemical properties of NSAIDs and the adsorption capacity of M–TDiCOF was illustrated. Moreover, the Independent gradient model based on Hirshfeld partition (IGMH) analysis revealed the interaction sites and the electrostatic potential (ESP) analysis highlighted the significance of electrostatic interactions. Finally, the adsorption mechanisms of M–TDiCOF are systematically confirmed. The abundant functional groups (guanidinium groups, hydroxyl groups, and aromatic groups) of M–TDiCOF facilitate electrostatic interactions, H-bond, π-π interactions, and ion exchange during water purification. Mung bean growth experiments verify the safety of M–TDiCOF system. [ABSTRACT FROM AUTHOR]

• The TiN/BiOBr piezo-photocatalyst was first reported. • The modification of TiN simultaneously improves piezo/photocatalytic properties. • DFT calculations verified that TiN extends piezoelectric field. • TiN/BiOBr showed an inspiring piezo-photocatalytic activity for SIZ degradation. Piezo-photocatalytic systems have the capacity to degrade environmental contaminants by exploiting mechanical and photonic energy. Herein, we report on a strategy for the modification of bismuth bromide oxide (BiOBr) with a non-noble metal plasma (titanium nitride (TiN)). The synthesized piezo-photocatalytic system demonstrated excellent performance for the degradation of sulfisoxazole (SIZ), where the 2-TiN/BiOBr samples exhibited a high degradation rate of 94.9 % in 70 min, with a rate constant that was 4.68 times higher than that of BiOBr. This improved catalytic performance was attributed to the localized surface plasmon resonance (LSPR) effect and high electronic conductivity of TiN, which improved the photocatalytic and piezoelectric properties of BiOBr. The hypothesis of an extended piezoelectric field was verified in conjunction with density functional theory (DFT) calculations. This work presents a new perspective for improved piezoelectric photocatalytic systems, which have great potential for utilizing solar and mechanical energy for environmental remediation. [ABSTRACT FROM AUTHOR]

Over the last few years, non-steroidal drugs (including ibuprofen (IBP)) have been used extensively due to the impacts of COVID-19, with the resulting environmental contamination attracting the attention of researchers. For this study, an ionic covalent organic framework (iCOF), synthesized from 1,2,4,5-tetrakis (4-formylphenyl) benzene (TFPB) and 1,3-diaminoguanidine hydrochloride (Dg Cl) under hydrothermal conditions, was employed for the effective elimination of non-steroidal anti-inflammatory drugs (NSAIDs) from aqueous media. COFs are relatively ordered spherical structures with excellent adsorption capacities for NSAIDs (IBP, diclofenac (DCF), and indomethacin (IDM)) with a removal rate of more than 99%. The adsorption kinetics and isotherm experiments of the COFs were investigated with IBP as a target contaminant, which revealed that its adsorption attained equilibrium within 120 min. Further, increased temperatures promoted the adsorption of IBP, where its maximum adsorption at 45 °C was calculated by the Langmuir isotherm model up to 434.78 mg·g-1. In addition, different pH, ionic influences, and repeated cycling experiments also confirmed the practical applicability of the COFs. Finally, it was demonstrated that the adsorption kinetics of IBP by TFPB-Dg Cl -COF could be explained by electrostatic and π-π interactions. [Display omitted] [ABSTRACT FROM AUTHOR]

• NCDs assisted construction of a stable oxygen vacancy layer in TiO 2 energy band. • NCDs/TiO 2 NA-V o electrodes displays excellent PEC activities under visible light. • Stable oxygen vacancy layer in TiO 2 accelerated the interfacial charge separation. • This work provides an effective strategy to regulate the defected TiO 2 electrodes. Oxygen vacancy was considered to act as electron scavengers, delaying electron-hole pair recombination for their critical impacts on the electronic-band structural modulation and optical absorption of a semiconductor. However, the generation and stabilization of oxygen vacancies (V o) remains a considerable challenge. Herein, a N-doped carbon dots/V o -rich TiO 2 nanowire array (NCDs/TiO 2 NA-V o) photoelectrode with a stable oxygen vacancy layer in TiO 2 energy band was constructed successfully by doping with NCDs. This optimized NCDs/TiO 2 NA-V o photoelectrode exhibited high activity and durability with a degradation reaction constant that was ∼ two and three fold higher than that of TiO 2 NA-V o and TiO 2 NA electrodes, respectively, and maintained a high degradation efficiency after eight consecutive degradation cycles. Moreover, the NCDs/TiO 2 NA-V o photoelectrode demonstrated a photocurrent density of 0.56 mA cm−2, which was more than three times that of TiO 2 NA electrode. These excellent visible light-driven photoelectrocatalysis (PEC) activities could be attributed to the stabilized and regulated oxygen vacancy layer induced by NCDs, which further accelerated the interfacial charge separation to generate more free radicals (e.g., OH, O 2 −, and 1O 2) confirmed by electron-spin resonance (ESR) and Photoluminescence Spectra (PL). Our work provides an effective strategy to regulate the defected TiO 2 electrodes in the applications of visible light-driven wastewater treatment. [ABSTRACT FROM AUTHOR]

In the present work, a cobalt-doped carbon nitride nanotubes (Co-CNt) was synthesized via self-assembly process. Contributed to the narrow band gap, enlarged specific surface area and abundant active sites, Co-CNt has excellent photoelectric properties and superior performance than pristine CN in sulfisoxazole (SIZ) degradation under blue light irradiation, which achieved 100% removal within 40 min. Meanwhile, the system not only exhibited practical applicability by efficiently degrading SIZ, but also generating high levels of H 2 O 2. Moreover, the Co-CNt/visible light system shows superior operability over a wide pH range, micro-concentration contaminants, various anions, water matrices and other sulfonamides with promising catalytic stability and applicability. The contribution of RSs in the degradation process were elucidated based on radical scavenging and spin-trapped tests, clarifying that O 2 ·- and h+ majorly dominated the process. In addition, 4 probable degradation pathways of SIZ were provided and the generated intermediates' toxicity were evaluated. Overall, this study successfully synthesized a self-assembled 1D tubular photocatalyst with Co-doped and demonstrated the potential Co-CNt/visible light system for environmental remediation, providing a promising approach for the development of photocatalysis. [Display omitted] • Innovatively synthesized cobalt-doped tubular carbon nitride through a "template-free" self-assembly process. • Tubularizaiton and metal doping greatly improved the photocatalytic properties while ensuring minimal Co leaching. • The Co-CNt/visible light system demonstrated dual-functionality of both pollutant degradation and H 2 O 2 generation. • The photocatalytic system has robust stability, strong environmental resistance and applicability. [ABSTRACT FROM AUTHOR]

• A novel phosphorus and oxygen co-doped g-C 3 N 4 (POCN) photocatalyst was prepared. • The POCN showed excellent photocatalytic activity. • The mechanism of the POCN photocatalyst was deduced. • O 2 − was the main reactive oxidative specie in the photocatalytic degradation. Non-metal doping has been frequently used in g-C 3 N 4 (CN) as a feasible and economical technique for maintaining its metal-free properties, while improving its photocatalytic performance. In this study, a novel phosphorus and oxygen co-doped graphitic carbon nitride (POCN) was successfully synthesized through a one-step thermal polymerization method and exhibited remarkable photocatalytic activity for the photocatalytic degradation of fluoroquinolones (FQs). The degradation rate of enrofloxacin (ENFX) was 6.2 times higher than that of CN. Based on the results of X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonance spectroscopy (NMR), P atoms replaced the corner and bay carbon sites, whereas O atoms replaced the nitrogen sites in the g-C 3 N 4 framework. The improvement of the photocatalytic effect of POCN0.01 was attributed to its narrow bandgap, effective charge separation and enhanced specific surface area. This is the first report to describe the use of phosphorus doping to promote the generation of reactive oxygen species (ROS). ROS scavenging tests revealed that O 2 − was the primary active species during the degradation of ENFX. Furthermore, pathways for the degradation of ENFX were proposed via the detection of intermediate products via HRAM LC–MS/MS and the prediction of active sites using the Fukui function. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • CuFe 2 O 4 modified g-C 3 N 4 was successfully synthesized and employed as visible light-responsive photocatalyst. • The combination of peroxydisulfate (PDS) enhanced the separation efficiency of photogenerated charges and induced the formation of SO 4 −. • Significant roles of reactive species were identified during the photocatalytic process. • The transformation pathways of propranolol (PRO) were proposed under the Vis/g-C 3 N 4 /CuFe 2 O 4 /PDS system. Abstract A copper ferrite modified graphitic carbon nitride (CuFe 2 O 4 /g-C 3 N 4) nanocomposite was successfully synthesized for the utilization as a visible-light responsive photocatalyst. The as-synthesized catalysts were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra (UV–vis/DRS), photoluminescence (PL) analysis, and an electrochemical workstation. Compared to g-C 3 N 4 and CuFe 2 O 4 , the CuFe 2 O 4 /g-C 3 N 4 composites possessed excellent photocatalytic performance for the destruction of propranolol (PRO). A removal efficiency of 82.2% was achieved with 1 g/L catalyst and 1 mM peroxydisulfate (PDS) under visible light irradiation (λ < 420 nm) within 120 min. The g-C 3 N 4 coupled with CuFe 2 O 4 improved the capacity for visible light capture, whereas the presence of PDS enhanced the transfer of photogenerated electron. Quenching experiments and electron spin resonance (ESR) suggested that the reactive oxygen species (ROS) were superoxide radicals (O 2 −), h+, hydroxyl radicals (OH), and sulfate radicals (SO 4 −). Moreover, the byproducts of PRO were investigated by HPLC-MS/MS, and the transformation pathways under the Vis/g-C 3 N 4 /CuFe 2 O 4 /PDS process were tentatively proposed based on the intermediates. The research provided a potential approach of CuFe 2 O 4 modified g-C 3 N 4 as a photocatalyst combined with PDS for the treatment of contaminated water. [ABSTRACT FROM AUTHOR]

The activation of molecular oxygen and generation of reactive oxygen species (ROS) play important roles in the efficient removal of contaminants from aqueous ecosystems. Herein, using a simple and rapid solvothermal process, we developed a chlorine-doped phenylethynylcopper (Cl/PPECu) photocatalyst and applied it to visible light degradation of sulfamethazine (SMT) in aqueous media. The Cl/PPECu was optimized to have a 2.52 times higher steady-state concentration of O 2 •- (3.62 × 10−5 M) and a 28.87 times higher degradation rate constant (0.2252 min−1) for SMT compared to pure PPECu. Further, the effectiveness of Cl/PPECu in treating sulfonamide antibiotics (SAs) in real water systems was verified through an investigation involving natural water bodies, SAs, and ambient sunlight. The energy band structure, DFT calculation and correlation heat map indicated that the addition of chlorine modulated the local electronic structure of PPECu, leading to an improvement in the electron-hole separation, enhanced the O 2 activation, and promoted the generation of ROSs. This study not only puts forward innovative ideas for the eco-compatible remediation of environmental pollution using PPECu, but also sheds new light on the activation of oxygen through elemental doping. [Display omitted] • Cl/PPECu composite was prepared by a facile method. • Cl/PPECu had superior ability to produce superoxide radicals and photocatalytic activity for SMT degradation. • Chlorine dopants regulated the band gap of the catalyst and improved photocatalytic molecular oxygen activation activity. • Detailed photocatalytic mechanisms and degradation pathways were proposed. [ABSTRACT FROM AUTHOR]

The peracetic acid (PAA)-activation process has attracted much attention in wastewater treatment. However, the low electron efficiency at the interface between heterogeneous catalysts and PAA has affected its practical application. For this study, we developed a carbon nitride hollow-nanotube catalysts with dispersed Cu(I) sites (Cu(I)-TCN) for the photocatalytic activation of PAA for antibiotics degradation. The obtained Cu(I)-TCN catalyst demonstrated an enhanced capacity for visible light harvesting along with increased charge transfer rates. Specifically, the developed Cu(I)-TCN/visible light/PAA system was able to completely remove antibiotics within 20 min, with a kinetic constant that was 25 times higher than a Cu(I)-TCN/visible light system, and 83 times higher than Cu(I)-TCN/PAA systems. Scavenging experiment and electron paramagnetic resonance (EPR) indicated that singlet oxygen was dominant reactive specie for sulfisoxazole (SIZ) removal. Besides, electrochemical tests and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy verified that the electron transfer efficiency of PAA activation was promoted due to the formation of inner-sphere interactions between PAA and Cu(I)-TCN, resulting in the quick removal of antibiotics. Further, after exposure to visible light, the Cu(I)-TCN excited photogenerated electrons which supplemented the electrons consumed in the reaction and drove the valence cycle of Cu ions. Overall, this research offered novel insights into the non-radical pathway for heterogeneous visible light-driven advanced oxidation processes and their potential for practical wastewater remediation. [Display omitted] • Carbon nitride hollow-nanotube with Cu(I) sites was prepared for antibiotics degradation. • Peracetic acid activation process dominated by 1O2 and electrons transfer. • Cu(I)-TCN-PAA* complexes was confirmed by ATR-FTIR and DFT calculations. • Photocatalysis assist facilitates the reduction of Cu(II) to Cu(I). [ABSTRACT FROM AUTHOR]

For this work, we employed n-type Bi 2 WO 6 and p-type PhC 2 Cu to formulate a direct Z-scheme Bi 2 WO 6 /PhC 2 Cu (PCBW) photocatalyst via simplified ultrasonic stirring technique. An optimal 0.6PCBW composite exhibited the capacity to rapidly photodegrade 2,4,6-TCP (98.6% in 120 min) under low-power blue LED light, which was 8.53 times and 12.53 times faster than for pristine PhC 2 Cu and Bi 2 WO 6 , respectively. Moreover, electron spin resonance (ESR), time-resolved PL spectra, and quantitative ROS tests indicated that the PCBW enhanced the separation capacity of photocarriers. It also more readily associated with dissolved oxygen in water to generate reactive oxygen species (ROS). Among them, the ability of PCBW to produce ·O 2 - in one hour was 12.07 times faster than for pure PhC 2 Cu. In addition, the H 2 O 2 formation rate and apparent quantum efficiency of PCBW are 10.73 times that of PhC 2 Cu, which indicates that PCBW not only has excellent photocatalytic performance, but also has outstanding ROS production ability. Furthermore, Ag photodeposition, in situ X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations were utilized to determine the photogenerated electron migration paths in the PCBW, which systematically confirmed that Z-scheme heterojunction were successfully formed. Finally, based on the intermediate products, three potential 2,4,6-TCP degradation pathways were proposed. [Display omitted] • Bi 2 WO 6 /PhC 2 Cu photocatalyst was synthesized by a facile ultrasonic stirring method. • Bi 2 WO 6 /PhC 2 Cu reserves ultrahigh redox activity of photogenerated carriers and optimized PhC 2 Cu and Bi 2 WO 6 properties. • Bi 2 WO 6 /PhC 2 Cu demonstrated outstanding photocatalytic performances under low power blue LED light. • The Z-scheme mechanism was certified via XPS, ESR, DFT calculation, and photo-deposition techniques. [ABSTRACT FROM AUTHOR]

Advanced oxidation processes (AOPs) are highly efficient for the removal of antibiotics from water. The activation of hydrogen peroxide (H 2 O 2) by ultraviolet (UV) has garnered increasing attention. This study describes the enhanced photochemical degradation of emerging contaminants in water using a UV-activated calcium peroxide (UV/CaO 2) system, wherein CaO 2 can gently produce H 2 O 2 when exposed to UV light. The UV/CaO 2 system can expeditiously and efficiently eradicate ciprofloxacin (CIP), in which hydroxyl radicals (•OH) and superoxide anions (O 2 •-) played critical roles. The superlative rate constant was 0.024 min−1 at an optimal dosage of 0.1 g L−1, which was a 16-fold increase over the rate of pure UV photolysis. The UV/CaO 2 system had an excellent defluorination capacity (80% within 60 min). Further, this technology was intensely evaluated over a wide range of pH for the removal of CIP, including H 2 O 2 yields, defluorination rates, as well as correlations with the reactive species generated during the reactions for numerical analysis. The UV/CaO 2 system had an excellent anti-interference capacity over a wide pH range. Three major degradation pathways were proposed for the degradation of CIP, together with predictions of the physiological toxicity of these transformation intermediates. This study provides strong technical support for the promotion of this UV/CaO 2 water treatment platform, as well as the decontamination and defluorination of water matrixes contaminated with fluoroquinolones. [Display omitted] • CaO 2 was applied to stimulate the degradation of Ciprofloxacin activated with UV. • Ciprofloxacin degradation performance hinged on the dosage of CaO 2 as well as pH. • Excellent defluorination performance in UV/CaO 2 system. • The primary reactive oxygen species were.•OH and O 2 •- in UV/CaO 2 system • The UV/CaO 2 system provided outstanding resistance to the impact of water conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hierarchical C 3 N 4 tubes with dual defect sites was successfully prepared. • Nv/Cy - tCN shows excellent photodegradation performance toward 11 types of PPCPs. • DFT calculations show that the dual defect sites can promote the O 2 activation. • The environmental application potential of Nv/Cy - tCN was evaluated in detail. Solar-driven photodegradation of pharmaceutical and personal care products (PPCPs) is an attractive strategy for environmental remediation but faces poor activity mainly due to the unsatisfied generation rate of active radicals. Herein, we design and synthesize a hierarchical C 3 N 4 tubes containing dual defect sites of nitrogen vacancy and cyano group (Nv/Cy-tCN) via an alkali-assisted strategy. Density functional theory calculations demonstrate that modification of dual defect sites boost the activation of molecular oxygen through the polarization of O-O bonds. Furthermore, the ability to separate carriers and absorb light can be enhanced by the creation of an electron-rich structure in Nv/Cy-tCN. Consequently, the Nv/Cy-tCN shows excellent photo-degradation performance for eleven types of PPCPs, affording a 100% removal rate toward diclofenac within 7 min of natural sunlight irradiation. The Nv/Cy-tCN system exhibited enhanced diclofenac degradation kinetics with a reaction rate constant of 0.055 min−1, which was 12.8 times higher than that of pristine carbon nitride (0.0043 min−1). Importantly, the impacts on real wastewater and the degradation of trace contaminants further support that this photocatalytic system could be effectively used to remediate PPCPs pollution in environmental waterways. [ABSTRACT FROM AUTHOR]

Z-scheme heterojunction-based photocatalysts typically have robust removal efficiencies for water contaminants. Herein, we employed p-type PhC 2 Cu and n-type UiO-66-NH 2 to develop a direct Z-scheme UiO-66-NH 2 /PhC 2 Cu photocatalyst with an ultrahigh redox potential for Cr(VI) photoreduction and norfloxacin (NOR) photodegradation. Moreover, UV–vis diffuse reflectance, photoelectrochemical measurements, photoluminescence (PL) spectra and electron spin resonance (ESR) technique revealed that the UiO-66-NH 2 /PhC 2 Cu composite boosted light capturing capacities to promote photocatalytic efficiencies. Strikingly, the optimized UiO-66-NH 2 /PhC 2 Cu50 wt% rapidly reduced Cr(VI) (96.2%, 15 min) and degraded NOR (97.9%, 60 min) under low-power blue LED light. In addition, the UiO-66-NH 2 /PhC 2 Cu photocatalyst also exhibited favorable mineralization capacity (78.4%, 120 min). Benefitting from the enhanced interfacial electron transfer and ultrahigh redox potential of the Z-scheme heterojunction, the UiO-66-NH 2 /PhC 2 Cu photocatalyst greatly enhanced the separation efficacies of photogenerated carriers. This resulting abundance of active species (e.g., e-, h+, O 2 •-, and •OH) were generated to photo-reduce Cr(VI) and photo-oxidize NOR. Base on the identified intermediates, four degradation pathways of NOR were proposed. Finally, the Z-scheme mechanism were systematically confirmed through X-ray photoelectron spectroscopy (XPS), ESR, cyclic voltammetry (CV) tests, and photodeposition techniques. [Display omitted] • UiO-66-NH 2 /PhC 2 Cu photocatalyst was synthesized by a facile method. • UiO-66-NH 2 /PhC 2 Cu exhibited ultrahigh redox potential and optimized PhC 2 Cu and UiO-66-NH 2 properties. • UiO-66-NH 2 /PhC 2 Cu demonstrated excellent photocatalytic activities under low power blue LED light. • The Z-scheme mechanism was confirmed via XPS, ESR, CV tests, and photodeposition techniques. [ABSTRACT FROM AUTHOR]

[Display omitted] • Doping of CQDs improved the photocatalytic activity of PDI. • The evolution processes of NPX were illustrated. • DFT calculations elucidated the photogenerated electron-hole separation. • PDI/CQDs membrane had excellent cycling and successive reaction property. Advanced efficacious catalytic technologies have the capacity to enhance the degradation of emerging anthropogenic contaminants. Herein, the supramolecular nanofibers, namely carbon quantum dots doped perylene diimide (PDI/CQDs), was prepared via a one-step acidification polymerization method. The results showed that the rate constants of naproxen (NPX) were of 3.50 times in contrast to pristine PDI. When the doping amount of CQDs on PDI was 2%, the half-life of NPX was only 0.66 min in the PDI/CQDs photocatalytic system. The main active substances in the photocatalytic degradation of NPX were h+, O 2 •−, 1O 2 , H 2 O 2 and •OH. Degradation mainly occurred through four paths, including the decarboxylation reaction, classical Ipso-substitution reaction, electron-dominated reaction, and intramolecular dehydration reaction paths. The obvious inhibitory effects of HA, Cl−, NO 2 – and HCO 3 – was observed, where a lower pH value was beneficial for the degradation of NPX. An overall mechanism was proposed through Density Functional Theory calculations of high-efficiency electron-hole separation of PDI/CQDs. To improve the nanomaterial applicability, PDI/CQDs cellulose acetate membrane was synthesized and used under different water conditions, which further revealed the stability and efficient of this membrane. Ultimately, the aggregate results provided basic supportive data for the remediation of contaminants in water and wastewater. [ABSTRACT FROM AUTHOR]

Advanced oxidation processes based on peroxymonosulfate (PMS) are an efficient strategy to eliminate environmental micropollutants. Carbon nanotubes (CNTs) have been used as activators for PMS, but they still suffer from complex preparation processes and suboptimal catalytic performance. In this study, nitrogen-doped CNTs encapsulating cobalt nanoparticles (CoNCT) were prepared by a facile and economical calcination method using graphitic carbon nitride as a precursor. As expected, this novel CoNCT catalyst could rapidly activate PMS, and the CoNCT/PMS system could efficiently degrade eight types of sulfonamide antibiotics. It should be noted that singlet oxygen rather than the conventional sulfate and hydroxyl radicals were the predominant reactive species in the CoNCT/PMS system, which revealed a non-radical mechanism for the activation of PMS by CNTs. With the benefit of this mechanism, the CoNCT/PMS system maintained good oxidation performance over a wide pH range and exhibited strong resistance to anions, dissolved organic matter, and real water matrixes. This work not only contributes to the development of efficient carbon nanotubes as PMS activators, but also provides comprehensive insights into the non-radical mechanism involved in advanced oxidation processes for environmental decontamination. [Display omitted] • N-doped CNTs wrapped with Co particles (CoNCT) were prepared by a facile method. • The CoNCT/PMS system exhibited excellent performance for sulfonamides oxidation. • The nonradical pathway dominated by 1O 2 was responsible for this oxidation process. • This system had good anti-interference ability to the effects of ambient factors. [ABSTRACT FROM AUTHOR]

[Display omitted] • AgBr/BiOBr-OV S-scheme heterojunction composite was prepared by a facile method. • The synergy of oxygen vacancies and S-scheme heterojunction promotes the exciton dissociation of AgBr/BiOBr-OVs heterojunctions. • The photocatalyst had superior photocatalytic activity for SIZ degradation. • Detailed photocatalytic mechanisms and degradation pathways were proposed. The Coulomb force of photogenerated electrons and holes induces exciton effects during the process of photocatalysis, which limits the performance of semiconductors in this regard, whereas the conversion of photocatalytic excitons to free carriers serves a key role in photocatalytic processes. Herein, an AgBr/BiOBr S-scheme heterojunction composite material with surface oxygen vacancies was synthesized by in situ hydrothermal method for the degradation of sulfonamide antibiotics. It was confirmed that the kinetic rate constant (K obs) for sulfisoxazole was 0.3199 min−1 under 15 min exposure to visible light, which was 72.7 and 52.4 times that of BiOBr (0.0044 min−1) and AgBr (0.0061 min−1), respectively. Significantly, the photoluminescence (PL) detection and experimental trapping detection verified that the introduction of oxygen vacancies (OV) and S-scheme heterojunctions enhanced exciton dissociation and carrier transfer, which facilitated the generation of reactive oxygen species (ROS). Therefore, the AgBr/BiOBr-OV offers an innovative vision for the creation of a synergistic S-scheme heterojunction and oxygen vacancy photocatalytic system for the efficient utilization of solar light and provides a promising solution for the remediation of contaminated water. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel BNRU photocatalyst was synthesized via a facile method. • Band structure optimization and dual-channel carrier transfers could be achieved in the BNRU. • BNRU possessed enhanced oxidation capacities and photocarriers production-separation efficiencies. • BNRU exhibited outstanding photocatalytic activities under visible and natural solar light. The synergistic enhancement of photocarriers production-separation and oxidation capacities of g-C 3 N 4 to improve its catalytic performance for environmental remediation remains a challenge. Herein, we prepared a novel boron nitride quantum dots (BNQDs)-decorated reduced ultrathin g-C 3 N 4 (BNRU) composite, toward achieving the above objective through the synergistic effects of defect engineering and BNQDs loading. By introducing the defects (nitrogen vacancies (NVs) and cyano group), the optimized band structure absorbed more photons and provided a stronger oxidation driving force (+2.15 V). Meanwhile, NVs and BNQDs formed distinct electron-hole transfer channels to facilitate photocarriers separation. Compared with ultrathin g-C 3 N 4 , the optimal 2BNRU showed a 1.7-folds higher carrier density, and the photocurrent density increased from 1.33 to 9.31 μA/cm2 under visible light exposure. Electron spin resonance and molecular probe spectroscopy results revealed that these enhanced properties endowed 2BNRU with the superior capacity to generate free radicals. The 2BNRU completely removed 10 mg/L of norfloxacin molecules at a kinetic rate of 0.3744 min−1, and the mineralization rate attained 46.9 % under 30 min of visible light irradiation. Meanwhile, the 2BNRU system exhibited promising feasibility for a simulated water treatment process. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C 3 N 4) is a promising candidate for photocatalysis, but exhibits moderate activity due to strongly bound excitons and sluggish charge migration. The dissociation of excitons to free electrons and holes is considered an effective strategy to enhance photocatalytic activity. Herein, a novel boron nitride quantum dots (BNQDs) modified P-doped g-C 3 N 4 photocatalyst (BQPN) was successfully prepared by thermal polymerization method. Photoluminescence techniques and photoelectrochemical tests demonstrated that the introduction of P atoms and BNQDs promoted the dissociation of excitons and the migration of photogenerated carriers. Specifically, theoretical calculations revealed that P substitutions were the sites of pooled electrons, while BNQDs were the excellent photogenerated hole extractors. Accordingly, compared with g-C 3 N 4 , the BQPN showed improved performance in degrading four non-steroidal anti-inflammatory drugs (NSAIDs) under visible light irradiation. This work not only establishes an in-depth understanding of excitonic regulation in g-C 3 N 4 , but also offers a promising photocatalytic technology for environmental remediation. [Display omitted] • BNQDs modified P-doped g-C 3 N 4 nanosheet was prepared by a facile method. • P doping and BNQDs loading boosted exciton dissociation and carrier transfer. • The photocatalyst had superior photocatalytic activity for NSAIDs degradation. • Detailed photocatalytic mechanisms and degradation pathways were proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • A porous Na bridged g-C 3 N 4 with N defects is constructed via one-step thermal polymerization. • The introduction of N defects and alkali Na create driving force and upgrade carrier concentration. • The robust dual-sites structure is beneficial to stabilizing the existence of ·OH. • The optimized structure shows superior photocatalytic activity for fluoroquinolone antibiotic. • The optimized photocatalyst shows a certain potential in real water environment. The inherent limitations of semiconductors include low carrier concentrations and the non-directional utilization of internal carriers, which exhibit sluggish photocatalyst-mediated redox activities. Here, a novel high-performance Na-bridged photocatalyst with nitrogen vacancies (WNCN) was successfully synthesized via one-step thermal-polymerization technique. The optimized carbon nitride can create an intrinsic driving force to achieve the directional separation of disordered carriers. Simultaneously, the bridged Na can serve as adsorptive site of fluoroquinolone antibiotics. Density function theory confirmed that the nitrogen vacancies served as reaction sites, which favored the activation of oxygen to regulate the formation of ·OH. Benefiting from the synergistic effects of dual-functional sites, the optimized structure exhibited superior photocatalytic activity (0.5932 min−1), achieving over 11 times the kinetic degradation efficacy for enrofloxacin in contrast to pristine CN (0.0514 min−1). The concept of the directional utilization of disordered charges may be extended to other photocatalysts, thereby guiding the development of more practical photocatalysts. [ABSTRACT FROM AUTHOR]

Herein, we designed and constructed an ultrathin porous phosphorus-doped g-C 3 N 4 nanosheet (PCN) bifunctional photocatalytic system for efficient production of H 2 O 2 and degradation of non-steroidal anti-inflammatory drugs in aqueous environment. The phosphorus atoms introduced in g-C 3 N 4 significantly improved the utilization of light, enhanced the adsorption capacity for O 2 , and inhibited the recombination of photogenerated carriers, thereby boosting the photocatalytic performance. Consequently, the optimized PCN photocatalyst produced 285.34 μM of H 2 O 2 under blue LED light irradiation, which was 3.41 times that of pristine g-C 3 N 4 , and its degradation rate constant for diclofenac (0.1248 min−1) was 46.22 times that of the g-C 3 N 4. Density functional theory (DFT) calculations suggested that phosphorus doping modulated the local electronic structure of g-C 3 N 4 , which improved the electron-hole separation and promoted the O 2 reduction reaction. This work comprehensively reveals the mechanisms of phosphorus doping on g-C 3 N 4 , while offering a promising strategy for addressing current energy demands and environmental remediation concerns. [Display omitted] • Ultrathin porous phosphorus-doped g-C 3 N 4 nanosheet was prepared by one-step method. • DFT calculations elucidated the transfer and separation of photoinduced carriers. • The photocatalyst exhibited high-efficiency H 2 O 2 production and NSAIDs degradation. • Detailed photocatalytic mechanisms were proposed for these two reaction processes. [ABSTRACT FROM AUTHOR]

Sulfonamides (SAs) have been of ecotoxicological concern for ambient ecosystems due to their widespread application in the veterinary industry. Herein, we developed a powerful advanced oxidation peracetic acid (PAA) activation process for the remediation of SAs by Co 3 O 4 with double-layered hollow structures (Co 3 O 4 DLHSs). Systematic characterization results revealed that the polyporous hollow hierarchical structure endows Co 3 O 4 DLHSs with abundant active reaction sites and enhanced mass transfer rate, which were conducive for improving the PAA activation efficiency. Laser flash photolysis experiment and mechanism studies indicated that organic radical species were dominant reactive species for SAs removal. The present system is also highly effective under natural water matrices and trace SAs concentration (20 μg/L) condition. More importantly, the chlorella acute toxicity of the SAs solution was eliminated during mineralization process, supporting this catalytic system may be efficaciously applied for the remediation of SAs contamination in ambient waterways. [Display omitted] • Co 3 O 4 DLHSs was firstly synthesized as the PAA activator, which displayed excellent capacity for Sulfonamides removal. • The in-depth understanding of the reaction mechanism of PAA activation process. • SAs transformation pathway and toxicity assessment were comprehensively analyzed. • The remediation of sulfonamides in practical wastewater treatment was achieved. [ABSTRACT FROM AUTHOR]

The development of efficacious photocatalysts for the elimination of contaminants in water remains a challenge. Herein, a promising Ag nanoparticles-decorated copper-phenylacetylide (Ag/PhC 2 Cu) plasmonic photocatalyst was fabricated for the reduction of hexavalent chromium (Cr(VI)) and degradation of pharmaceutical and personal care products (PPCPs). Typically, the optimized 5Ag/PhC 2 Cu could rapidly reduce Cr(VI) (98.1% within 12 min), and degrade norfloxacin (NOR) (100% within 40 min) with a 56.2% mineralization rate under visible light. The superior photocatalytic activity of Ag/PhC 2 Cu was attributed to the synergistic effects of the highly reducing photoinduced electrons conferred by the PhC 2 Cu (−1.98 eV), and Ag nanoparticles in promoting photocarrier separation and enhancing solar-energy-conversion efficiencies. Subsequently, the photocatalytic reaction mechanism of Ag/PhC 2 Cu was investigated. It was found that e- and O 2 •- were the main reactive species for Cr(VI) reduction, while O 2 •- and h+ were primarily responsible for the degradation of NOR. Of note, the Ag/PhC 2 Cu system could effectively generate H 2 O 2 and partially decomposed it to •OH, which might be involved in NOR mineralization. This study not only demonstrates a highly active photocatalytic system for the remediation of environmental pollution and sustainable solar-to-chemical energy conversion, but contributes to the future exploration of multifunctional plasmonic photocatalysts. [Display omitted] • A plasmonic Ag/PhC 2 Cu photocatalyst was synthesized via a facile method. • Ag/PhC 2 Cu possessed efficient photocarrier separation and solar-energy-conversion. • Ag/PhC 2 Cu exhibited outstanding photocatalytic redox activity under visible light. [ABSTRACT FROM AUTHOR]

Abstract: TiO2 nanotubes have been synthesized by a hydrothermal method and their surface has been effectively modified with silane coupling agents. TiO2 nanotubes–polyurethane photocatalytic composites were then successfully synthesized through a series of activation reactions using polyurethane (PU) membrane as a solid carrier. All of these products have been characterized and identified by means of scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). The results have shown that the TiO2 nanotubes treated by silicon alkylation could efficiently combine with the solid carrier (PU) and that the surface multilayer structure was very stable and compact. In addition, the new composite showed very good photocatalytic activity and was recyclable, which was demonstrated by the photocatalytic degradation of Rhodamine B. [Copyright &y& Elsevier]

The development of conjugated polymers with intramolecular donor–acceptor (D-A) units has the capacity to enhance the photocatalytic performance of carbon nitride (g-C 3 N 4) for the removal of antibiotics from ambient ecosystems. This strategy addresses the challenge of narrowing the band gap of g-C 3 N 4 while maintaining its high LUMO position. For this study, we introduced the above donor units into g-C 3 N 4 to construct intramolecular D-A structures through the copolymerization of dicyandiamide with creatinine, which strategically extended light absorption into the green region and expedited photoelectron separation. The introduction of electron donor blocks kept the LUMO distributed on the melem, which maintained the high LUMO energy level of the copolymer with the potential to generate oxygen radicals. The as-prepared porous D-A conjugated polymer enhanced the photocatalytic degradation of sulfisoxazole with kinetic constants 5.6 times higher than that of g-C 3 N 4 under blue light and 15.3 times higher under green light. Furthermore, we surveyed the degradation mechanism including the effective active species and degradation pathways. This study offers a new perspective for the synchronous construction of a porous intramolecular D-A conjugated polymer to enhance water treatment and environmental remediation capacities. [Display omitted] • A novel porous intramolecular donor-acceptor conjugated copolymer was prepared by copolymerization. • The electron donor block was introduced to maintain the high LUMO level for degrading antibiotics. • The CCN3 exhibited higher sulfisoxazole degradation rates under blue and green light. • The degradation mechanism of sulfisoxazole involved with reactive species and degradation pathways were investigated. [ABSTRACT FROM AUTHOR]

Atomic hydrogen (H*) plays a vital role in the synchronous redox of metallic ions and organic molecules. However, H* is extremely unstable as it is easily converted to hydrogen. Herein, we designed a novel strategy for the effective stabilization of H* to enhance its utility. The synthesized Pd nanoparticles grown on the defective MoS 2 (DMS) of TiO 2 nanowire arrays (TNA) (TNA/DMS/Pd) photocathode exhibited rapid Cr(VI) reduction (~95% in 10 min) and bisphenol A (BPA) oxidation (~97% in 30 min), with the kinetic constants almost 24- and 6-fold higher than those of the TNA photocathode, respectively. This superior performances could be attributed to: (i) the generated interface heterojunctions between TNA and DMS boosted the separation efficiencies of photogenerated electrons, thereby supplying abundant valance electrons to lower the overpotential to create a suitable microenvironment for H* generation; (ii) the stabilization of H* by Pd nanoparticles resulted in a significant increase in the yield of hydroxyl radical (•OH). This research provides a new strategy for the effective utilization of H* toward rapid reduction of heavy metals and synchronous oxidation of the refractory organics. [Display omitted] • The heterojunction of TNA/DMS created a microenvironment for H* generation. • The stabilization of H* by Pd nanoparticles increased the quantity of •OH. • The H* and •OH collectively dominated the synchronous redox reactions. • The Cr(VI) reduction and synchronous BPA oxidation processes were analyzed. [ABSTRACT FROM AUTHOR]

Herein, supporting g-C 3 N 4 embedded with benzene-ring (BCN) on P-modified g-C 3 N 4 (PCN) successfully synthesized the homogeneous photocatalyst BCN/PCN (PBCN) via a simple thermal polymerization reaction. Under blue-light (LED) irradiation, the optimized PBCN (0.448 min−1) demonstrated excellent photocatalytic performance, attaining over 74 times the degradation rate for sulfisoxazole (SSZ) in contrast to non-functionalized g-C 3 N 4 (CN, 0.006 min−1). Theoretical calculations revealed that the substitution of heterocyclic rings in the g-C 3 N 4 triazine networks with benzene-rings enabled them to serve as electron donors, while promoting photoinduced spatial charge dissociation. Further, the carrier PCN tended to serve as electron acceptors to form electron-rich corner-phosphorous sites. Reactive species experiments demonstrate that the O 2 ˙− and h+ constituted the primary photocatalytic mechanism of SSZ degradation. The potential SSZ degradation routes were predicted based on the transformation products via mass spectrometry. Finally, the composite materials also exhibited excellent photocatalytic activity in the conversion of solar energy to chemical energy (H 2 O 2). This study guides the rational modification of g-C 3 N 4 -based semiconductors to achieve green energy production and beneficial ecological applications. [Display omitted] • A novel double-functionalized PBCN composite is fabricated via a three-step process. • DFT elucidates the alteration of electronic structure promotes the charge transfer. • PBCN 0.05 delivers a high SSZ degradation rate over 74 times better than bulk CN. • The mechanism for SSZ degradation by the light/PBCN 0.05 system is proposed. • PBCN 0.05 exhibits great photocatalytic performance for H 2 O 2 production. [ABSTRACT FROM AUTHOR]

[Display omitted] • The iCOFs were exploited as adsorbents for the removal of NSAIDs. • TPA-TG Cl showed a maximum adsorption capacity of 724.64 mg·g−1 for diclofenac sodium, and 240.96 mg·g−1 for ketoprofen, respectively. • The adsorption mechanism of iCOFs was attributed to electrostatic and π-π stacking interactions. The presence of non-steroidal anti-inflammatory drugs (NSAIDs) is ubiquitous in ambient waterways due to their excessive consumption, which poses deleterious risks to human health and ecosystems. In this work, two classes of ionic covalent organic frameworks with different pore sizes (iCOFs) [TPA (terephthaldicarboxaldehyde)-TG Cl (triaminoguanidinium chloride) and BPDA (4,4′-Biphenyldicarboxaldehyde)-TG Cl ], which is consisted of guanidine moieties as intrinsic cationic knots and different chain length dialdehydes, were innovatively exploited as adsorbents for the removal of NSAIDs. Studies revealed that the prepared iCOFs had a strong affinity for NSAIDs, particularly for diclofenac sodium (DCF) and ketoprofen (KT). The adsorption isotherms and kinetics data of both these iCOFs were in alignment with the Langmuir model and pseudo-second-order model, respectively. Guanidine-based iCOF knots trigger electrostatic interactions, which are the primarily intrinsic driving force that facilitates the efficient removal of DCF and KT. Furthermore, π-π stacking interactions are proposed based on iCOF skeletons. Additionally, TPA-TG Cl was more preponderantly adsorptive toward DCF and KT, with maximum adsorption capacities of 724.64 mg·g−1 for DCF and 240.96 mg·g−1 for KT. Among them, the maximum adsorption capacity of DCF on TPA-TG Cl was 27 times higher than that of carbon nanospheres, almost triple that of a magnetic cellulose ionomer/LDH, and two-fold higher than that of UiO-66-SO 3 H. Finally, the TPA-TG Cl effectively achieved five adsorption–desorption cycles. Ultimately, iCOFs simultaneously meet the demands of structural regularity and accessibility to functional sites. Thus, they can be considered as highly efficient and recyclable adsorbents with potential applications for the remediation of the water environment, while providing a scientific basis for functional material design. [ABSTRACT FROM AUTHOR]

Graphical abstract illustrates the Cr (VI) adsorption mechanism of Tp-DG Cl in aqueous body. The waste water containing Cr (VI) oxoanions could be purified when contacting the material. At the time, the Cr (VI) oxoanions were adsorbed on Tp-DG Cl owing to the directional hydrogen bonds, and Cl- of Tp-DG Cl would be released into the water because of the ion exchange between Cr (VI) oxoanions and Cl-. [Display omitted] • Guanidinium groups of Tp-DG Cl were employed to remove chromate selectively. • The adsorption ability of Tp-DG Cl remained at a high level subsequent to five cycles. • Tp-DG Cl showed remarkable selectivity and high adsorption capacity of 336.04 mg/g for Cr (VI). • The excellent adsorption performance of Tp-DG Cl was systematically studied. • The adsorption mechanism is dominant by ion exchange and electrostatic attraction. In consideration of the serious environmental issues caused by heavy metals, novel nanomaterials have been developed and applied as highly selective adsorbents with the capacity to eliminate heavy metal ions in ambient ecosystems. Ionic covalent organic frameworks (I-COFs) serve as an emerging species of functional nanomaterials that inherently possess ionic interfaces that interact strongly with oppositely charged ionic species. In this work, a guanidinium-based COF with a β-ketoenamine linkage (Tp-DG Cl) was synthesized using a solvothermal method. The obtained Tp-DG Cl colligated four advantages, namely easy synthesis, high selectivity (for Cr (VI)), excellent adsorption (360.02 mg/g calculated by Langmuir model), and good recyclability (five cycles), which enables it to serve as a reliable sorbent for wastewater treatment. Owing to the stable and selective binding affinities between tetrahedral oxoanions and diiminoguanidinium groups, Tp-DG Cl exhibited an outstanding adsorption capacity for Cr (VI). Subsequent to five cycles, the adsorption performance of Tp-DG Cl remained at a high level (85%), which demonstrated an excellent regenerative capacity by supplementing Cl- to the Tp-DG Cl after adsorption. Consequently, Tp-DG Cl revealed a strong potential for broad applications in wastewater remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] • 4-Phenoxyphenol-modified g-C 3 N 4 (PCN) was synthesized via a facile hydrothermal–copolymerization method. • PCN photocatalyst demonstrated enhanced photocatalytic activity for the degradation of SAs. • The faster charge separation efficiency of PCN promoted the formation of additional reactive oxygen species. • The potential transformation pathways of SIZ were infered by FMOT and HRAM LC–MS/MS. Significant quantities of sulfonamide antibiotics are continuously released into the ambient environment; thus, they have emerged as serious pollutants that may inflict ecological damage. Herein, 4-phenoxyphenol-modified g-C 3 N 4 (PCN) was initially prepared via the copolymerization of dicyandiamide and 4-phenoxyphenol, which demonstrated excellent performance for light-harvesting and the promotion of photon-generated carrier separation. Optimized PCN exhibited 4.5-fold higher photocatalytic degradation activity for sulfisoxazole (SIZ) than pure g-C 3 N 4 under blue-light (LED) irradiation. Among SIZ, sulfapyridine (SPD), sulfadiazine (SDZ) and sulfadimethazine (SMZ), SIZ and SMZ are more vulnerable to attack in PCN photocatalytic system due to structure containing methyl. Electron spin resonance and photoelectrochemical experiments revealed that the faster charge separation of PCN promoted the formation of additional reactive oxygen species. Moreover, the potential transformation pathways of SIZ were hypothesized through the frontier molecular orbital theory and HRAM LC-MS/MS. Hence, the present work is expected to be of important reference value for sustainable environmental restoration. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbon quantum dots-modified reduced ultrathin g-C 3 N 4 (RUCN/CQD) was prepared with facile method. • The RUCN/CQD possessed enhanced photoresponse and photoredox activities. • The RUCN/CQD exhibited superior photocatalytic activities in simulated natural conditions. Graphitic carbon nitride (g-C 3 N 4) has been extensively applied for the photocatalytic degradation of pharmaceuticals and personal care products (PPCPs); however, its catalytic performance remains restricted by a poor photoresponse and modest photoredox capacity toward the generation of free radicals. Herein, a novel carbon quantum dots-modified reduced ultrathin g-C 3 N 4 (RUCN/CQD) photocatalyst was successfully synthesized, with the capacity for direct •OH and O 2 •− yields and a broad-spectrum response. Upon broad-spectrum light irradiation, the RUCN/CQD demonstrated a 100% removal rate for diclofenac (DCF) within six min. This remarkable performance was attributed to a customized band structure with a thermodynamic driving potential for the generation of •OH, CQD with an effective electron transfer capacity for promotional formation of O 2 •−, and ultrathin porous structure with abundant reaction sites. Simultaneously, the up-converted fluorescent properties of the CQD endowed the photocatalyst with a broad-spectrum response. The RUCN/CQD system also exhibited superior photocatalytic activities under simulated natural conditions, which implied an immense potential for the remediation of PPCPs in ambient waterways. [ABSTRACT FROM AUTHOR]

Bismuth oxyiodide (BiOI) has garnered intense attention in the field of photocatalysis for environmental remediation; however, it suffers from a high electron-hole recombination rate. In this study, for the first time, we report on a facile strategy for the creation of oxygen vacancies in BiOI via strontium (Sr2+) doping. The as-prepared 0.45-SrBiOI demonstrated significantly enhanced photocatalytic degradation of indometacin under visible light exposure, which was almost 10 folds higher than pristine BiOI. This augmented photocatalytic performance was ascribed to the accelerated separation of charge carriers by oxygen vacancies, as well as Sr ion trapping electrons. Reactive species determination experiments revealed that O 2 ▪−, 1O 2 , and h+ were the dominant active species. Finally, potential indometacin degradation pathways were proposed based on the identification of degradation by-products and theoretical calculations. This study offers new perspectives for the synthesis of highly efficient and cost effective BiOI-based photocatalysts, and provides a promising strategy toward advanced environmental remediation. [Display omitted] • A novel visible-light-driven SrBiOI photocatalyst along with OVs was prepared via a convenient process. • The photocatalyst showed enhanced photocatalytic activity in IDM degradation. • The roles of reactive species and degradation mechanism were identified during the photocatalytic process. • HRAM LC-MS/MS and ALIE calculation helped to explain the degradation pathways. [ABSTRACT FROM AUTHOR]

• Both pristine and oxidized C 3 N 4 can be transformed under UV-irradiation. • C 3 N 4 was finally mineralized into NO 3 −, CO 2 , and H 2 O through the circular reactions. • Photo-transformation impacts water stability of C 3 N 4. • Photo-transformation greatly reduced the photocatalytic activity of C 3 N 4. In this study, the photo-transformations of bulk C 3 N 4 (CN) and oxidized C 3 N 4 (OCN) under UV-irradiation were examined. Through NO 3 − release measurements, we found that the photo-transformation rate of OCN is higher than that of CN. Various characterization results revealed the structural and chemical properties changes of CN and OCN after photo-transformation. We proposed that under reactive oxygen species attack, CN and OCN were gradually broken into smaller fragments and finally mineralized into NO 3 -, CO 2 , and H 2 O through the circular reactions of deamination-hydroxylation-decarboxylation. Through the zeta potential measurements and sedimentation experiments, the influence of photo-transformation on the water stabilities of CN and OCN were assessed. The stability of CN in water increased while the water stability of OCN decreased after photo-transformation, implying that the changes to C 3 N 4 -based materials caused by photo-transformation may significantly impact their environmental behaviors. Moreover, the photocatalytic activities of the photo-transformed OCN and CN substantially decreased, indicating that the structural changes might be the main reason for their photocatalytic activity loss. These findings highlight the non-negligible influence of photo-transformation on the fate of C 3 N 4 in aquatic environments, as well as on the photochemical stability during its use. [ABSTRACT FROM AUTHOR]

• A novel photocatalyst (30 % Ag 2 WO 4 /PCN) was successfully synthesized. • The photocatalyst showed remarkable photocatalytic activity under visible-light. • O 2 – was the main reactive species in the IDM photocatalytic degradation. • The mechanism for IDM degradation by the 30 % Ag 2 WO 4 /PCN was proposed. As a metal-free photocatalyst, the photocatalytic activity of graphitic carbon nitride (g-C 3 N 4) remains restricted due to an insufficient visible-light absorption capacity, the rapid recombination of photoinduced carriers, and low surface area. Consequently, P-doped g-C 3 N 4 (PCN) was successfully prepared via a single -step thermal polymerization technique using phytic acid biomass and urea, which exhibited remarkable photocatalytic activity for the degradation of indometacin (IDM). The IDM degradation rate was 7.1 times greater than that of pristine g-C 3 N 4 (CN). Furthermore, Ag 2 WO 4 was loaded onto the surface of the PCN, which formed a Z-scheme heterostructure that promoted the separation of photogenerated carriers. According to analyses of the chemical binding states of PCN, P atoms replaced carbon atoms in the CN framework. According to electron localization function analysis, the low ELF values of P-N facilitated the transfer of photoelectrons. The results of active species scavenging experiments confirmed that superoxide radicals were the primary active species in the photocatalytic degradation system. Finally, the photocatalytic degradation pathways of IDM were predicted through the identification of by-products and IDM reaction sites. [ABSTRACT FROM AUTHOR]