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Peroxymonosulfate (PMS, SO52−)-based oxidation is an efficient pathway for degrading organic pollutants, but it still suffers from slow degradation efficiency and low PMS utilization. In this work, we report the preparation of porous Fe-doped g-C3N4 catalysts by one-step thermal polymerization using urea and transition metal salts as precursors and investigate the effect of atmosphere conditions (air and nitrogen) on the catalytic performance. Systematic characterizations show that Fe-doped g-C3N4 prepared in air (FeNx-CNO) has a larger specific surface area (136.2 m2 g−1) and more oxygen vacancies than that prepared in N2 (FeNx-CNN, 74.2 m2 g−1), giving it more active sites to participate in the reaction. Meanwhile, FeNx-CNO inhibits the recombination of photogenerated carriers and improves the light utilization. The redox cycling of Fe(III) and Fe(II) species in the photocatalytic system ensures the continuous generation of SO5•− and SO4•−. Therefore, FeNx-CNO can remove CBZ up to 96% within 20 min, which is 3.4 times higher than that of CNO and 3.1 times higher than that of FeNx-CNN, and the degradation efficiency can still retain 93% after 10 cycles of reaction. This study provides an economical and efficient method for photocatalysis in the degradation of medicines in contaminated water. [ABSTRACT FROM AUTHOR]

Iron (II) phthalocyanine (FePc) is loaded on the surface of the tourmaline (TM) by the reflow method to obtain FePc/TM. This research effectively prevents the π-π stacking of FePc, increased the effective utilization rate of PMS activation under solar light, and further improved the catalytic performance of the catalytic system. The catalytic oxidation efficiency of FePc/TM on carbamazepine (CBZ) and sulfadiazine (SD) can reach 99% under solar light for 15 and 5 min, the total organic carbon (TOC) removal rate can reach 58% and 69% under solar light for 120 min. After 6 cycles, the CBZ removal rate remained above 95%. In addition, the FePc/TM catalytic system has an excellent removal rate for other pharmaceuticals. The results of spin-trapped electron paramagnetic resonance and classical quenching experiments show that FePc/TM can effectively activate PMS to generate active species under solar light, including superoxide radical (•O2−), singlet oxygen (1O2), hydroxyl radicals(•OH), and sulphate radicals (SO4•−). The intermediates of CBZ were identified by Ultra-high performance liquid chromatography and high resolution mass spectrometry, and the degradation pathway was proposed. As the reaction progresses, all CBZ and intermediates are reduced and converted into small acids, or mineralized to H2O, CO2. This work provides an alternative method for the design of efficient activation of PMS activation catalysts under solar light to eliminate residual pharmaceuticals in actual water bodies. [ABSTRACT FROM AUTHOR]

The selective elimination of recalcitrant organic pollutants in high backgrounds of complex constituents has proven a significant challenge. Inspired by the naturally occurring oxidation reactions catalyzed by metalloporphyrin-based enzymes, where the target substrates can be oxidized selectively due to the specific enzyme environment and the axial fifth ligands of metalloporphyrins, we developed a bioinspired catalytic system based on cellulosic fiber-boned cobalt phthalocyanine for capturing and oxidizing dyes by H 2 O 2 activation in the presence of high additive concentrations. In this system, the cellulosic fibers provided the amorphous regions, functioning as cavities in the same manner as the protein backbones of enzymes for the selective accessibility of dyes; cobalt phthalocyanine was introduced as the catalytic entity; and linear alkylbenzene sulfonate (one of the most widespread surfactants in industrial and domestic wastewater) was employed as the fifth ligand to help generate high-valent cobalt-oxo intermediates by the heterolytic cleavage of the peroxide O O bond. According to detailed density functional theory calculations, the spin populations are predominantly located around the cobalt-oxo center, achieving an electrophilic attack on the electron-rich azo bond and the aromatic ring of the target model dyes. [ABSTRACT FROM AUTHOR]

• β-FeOOH@g-C 3 N 4 composite catalyst was constructed by in situ stable growth. • β-FeOOH@g-C 3 N 4 presented excellent stability and efficiency for CBZ elimination. • Multi-path activation of PMS enhanced the catalytic oxidation efficiency. • SO 4 •− and •OH contribute to the deep oxidation of CBZ. • An alternative method was provided for the elimination of refractory emerging contaminants. Peroxymonosulfate (PMS) activation with the generation of strongly oxidizing hydroxyl radicals (•OH) and sulfate radicals (SO 4 •−) has attracted widespread attention for the elimination of organic contaminants. However, the design of an eco-friendly catalytic system with high mineralization rate and high stability remains a challenge. Here, an iron-based photocatalyst (β-FeOOH@g-C 3 N 4) for the activation of PMS was prepared by a cyclic microwave-assisted reaction, whereby Fe3+ was introduced at the nitrogen sites of g-C 3 N 4 , resulting in in situ growth and a uniform distribution of nano-β-FeOOH thereon. β-FeOOH@g-C 3 N 4 maintained high catalytic activity after acid treatment or repeated tests, demonstrating excellent stability and reusability. Moreover, compared with the catalytic systems with β-FeOOH or g-C 3 N 4 alone, the catalytic activity of β-FeOOH@g-C 3 N 4 was increased 5–10 times for the catalytic oxidation of carbamazepine (CBZ) and other emerging contaminants under solar irradiation. Importantly, the CBZ mineralization rate with the β-FeOOH@g-C 3 N 4 /PMS system under solar irradiation was as high as 92%. From the results of electron paramagnetic resonance spectroscopy and radical trapping experiments, large amounts of O 2 •−, 1O 2 , and FeV = O are present at the beginning of the reaction, which contribute to the rapid oxidative removal of CBZ, while SO 4 •− and •OH contribute to the deep oxidation, leading to a significantly enhanced total organic carbon (TOC) removal efficiency. This work provides an alternative method for the design of a highly efficient and stable catalyst for PMS activation to eliminate emerging contaminants. [ABSTRACT FROM AUTHOR]

• g-C 3 N 4 -TiO 2 @LMPET composite was constructed by using g-C 3 N 4 as an isolation layer. • The presence of g-C 3 N 4 effectively prevented the oxidation damage of PET by OH. • The catalytic performance was enhanced by the combination between g-C 3 N 4 and TiO 2. • The deep oxidation of refractory contaminants was achieved under solar irradiation. • Provide a feasible method for constructing efficient and stable supported catalysts. Solar-driven photocatalysis has shown tremendous potential for environmental remediation, but photocatalysts with the strong oxidation ability usually destroy some organic carriers. Herein, we constructed a graphitic carbon nitride (g-C 3 N 4)-shielding polyester fiber (PET)/titanium dioxide (TiO 2) composite (g-C 3 N 4 -TiO 2 @LMPET) by using g-C 3 N 4 as an isolation layer to protect the PET from the oxidation damage by hydroxyl radicals (OH). The results of photoluminescence and photocurrent indicated that the g-C 3 N 4 -TiO 2 @LMPET has lower photogenerated charge recombination rate. Meanwhile, g-C 3 N 4 broadens the absorption range of the composite to visible region. Therefore, the g-C 3 N 4 -TiO 2 @LMPET composite exhibited a significantly enhanced photocatalytic performance toward the degradation of sulfaquinoxaline (SQX) and thiamethoxam under solar irradiation. Moreover, the g-C 3 N 4 -TiO 2 @LMPET exhibited good repeatability in cyclic experiments. Finally, the possible degradation pathways and mechanisms of SQX and thiamethoxam were proposed. Overall, our work provides a feasible method for constructing efficient and stable photocatalytic materials to eliminating emerging contaminants. [ABSTRACT FROM AUTHOR]

Metal phthalocyanine has been extensively studied as a catalyst for degradation of carbamazepine (CBZ). However, metal phthalocyanine tends to undergo their own dimerization or polymerization, thereby reducing their activity points and affecting their catalytic properties. In this study, a catalytic system consisting of O-bridged iron perfluorophthalocyanine dimers (FePcF 16 -O-FePcF 16), multi-walled carbon nanotubes (MWCNTs) and H 2 O 2 was proposed. The results showed MWCNTs loaded with FePcF 16 -O-FePcF 16 can achieve excellent degradation of CBZ with smaller dosages of FePcF 16 -O-FePcF 16 and H 2 O 2 , and milder reaction temperatures. In addition, the results of experiments revealed the reaction mechanism of non-hydroxyl radicals. The highly oxidized high-valent iron-oxo (Fe(IV)=O) species was the main reactive species in the FePcF 16 -O-FePcF 16 /MWCNTs/H 2 O 2 system. It is noteworthy that MWCNTs can improve the dispersion of FePcF 16 -O-FePcF 16 , contributing to the production of highly oxidized Fe(IV)=O. Then, the pathway of CBZ oxidative degradation was speculated, and the study results also provide new ideas for metal phthalocyanine-loaded carbon materials to degrade emerging pollutants. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • g-C 3 N 4 -IMA-FePcCl 16 was prepared by axial coordination. • The spectral response region of g-C 3 N 4 was broadened. • The separation rate of photogenerated electron-hole pairs was promoted. • g-C 3 N 4 -IMA-FePcCl 16 exhibited a high activity over a broader pH range. • Synergistic photocatalysis mechanism of multiple active species to eliminate CBZ. Abstract Utilizing peroxymonosulfate (PMS)-based advanced oxidation processes to remove emerging contaminants in water has received widespread attention. In this study, g-C 3 N 4 -IMA-FePcCl 16 that was fabricated by axial coordination was applied to activate PMS for carbamazepine (CBZ) degradation. The introduction of imidazole-based ligand (IMA) and iron hexadecachlorophthalocyanine (FePcCl 16) facilitates the photogenerated electron-hole pairs separation of g-C 3 N 4 and broadens the visible-light response range. The coordination structure was characterized by X-ray diffraction and X-ray photoelectron spectroscopy. Photocatalytic experiments demonstrated that g-C 3 N 4 -IMA-FePcCl 16 can highly effective eliminate CBZ with a removal of ∼95% within 25 min in the presence of PMS. The effects of various experimental parameters on the CBZ degradation were investigated, such as the loading amount of FePcCl 16 , pH, PMS dosage and anions. It is noteworthy that Cl− has a positive effect on the degradation of CBZ. Another interesting finding is that the degradation of CBZ is attributed to the synergistic effect of multiple active species, which is confirmed by gas chromatography-mass spectrometry, electron paramagnetic resonance and radical quenching tests. Superoxide radicals (O 2 −) and singlet oxygen (1O 2) are the dominated active species. This work offers a novel idea for the rational design of high-efficiency photocatalysts for wastewater remediation. [ABSTRACT FROM AUTHOR]

Phthalocyanine has been used widely as an oxidation catalyst, e.g., in wastewater treatment. It has become important and necessary to study phthalocyanine derivatives, to understand the potential effect they may have. Despite the fact that phthalocyanine dimers are easy to generate, such complexes have been ignored as catalysts. We prepared O-bridged iron perfluorophthalocyanine dimers (FePcF 16 -O-FePcF 16 ). Ultraviolet–visible, X-ray diffractometry, X-ray photoelectron spectroscopy, density-functional theory analysis and electrospray ionization–mass spectrometry technology assisted by pyridine ligands have been used to identify the structure of FePcF 16 -O-FePcF 16. Carbamazepine selected as a model pollutant could be effectively oxidized in the system with FePcF 16 -O-FePcF 16 and H 2 O 2 . Electron paramagnetic resonance data indicated an active center that was different from OH in the Fenton reaction. Electrospray ionization–mass spectrometry detected the generation of high-valent diiron-oxo species, which implies that carbamazepine degradation was accomplished by the attack of Fe IV O Fe IV O in the FePcF 16 -O-FePcF 16 /H 2 O 2 system. Thus, we identified an O-bridge iron perfluorophthalocyanine dimer and proposed a catalytic mechanism. These results may provide a novel explanation for the oxidative mechanism. [ABSTRACT FROM AUTHOR]

The development of advanced oxidation processes to generate reactive oxygen species (ROS) has been one of the most important and great challenging goals in environmental catalysis field. Herein, a representative of persistent free radicals (PFRs), activated carbon fibers (ACFs), was innovatively employed to construct a novel and outstanding catalytic system, Cit-Fe@ACFs/AA/H 2 O 2 , in which PFRs act as an electron sink to release electrons to Cit-Fe (“discharging”), thus accelerating the reaction rate-determining step of Cit-Fe III to Cit-Fe II . Meanwhile, ascorbic acid (AA) serves as an electron donor provides electrons to ACFs to supply the consumed PFRs (“charging”). Previously, AA was mainly reported to be a ROS scavenger instead. Remarkably, in our system, the PFRs coupled with AA enabled unblocked electron transfer, strongly improving the generation of ROS ( OH), allowing for an extreme rate enhancement in oxidative decomposition of organic contaminants by hundreds of times compared with that of the sole Cit-Fe/H 2 O 2 system. [ABSTRACT FROM AUTHOR]

The development of coordination complexes to activate hydrogen peroxide (H 2 O 2 ) selectively is a goal that has long been pursued. As highly reactive intermediates, the high-valent metal-oxo species play important roles in many biological and industrial catalytic oxidation processes. To improve the catalytic efficiency of metal complexes, the peroxide O O bond should be cleaved heterolytically to decrease the decomposition of H 2 O 2 into O 2 and H 2 O. In this work, we provide a simple method to obtain coordination complex catalysts based on iminodiacetic acid (IDA), copper(II) ions and pyridine derivatives. Catalytic activity tests showed that the introduction of 4-aminopyridine ligands resulted in an enhanced catalytic activity of the IDA/Cu(II)/4-ampy complex. A series of designed experiments proved that high-valent copper-oxo species ([ O Cu III (IDA)(4-ampy) 2 ] species) were formed in the IDA/Cu(II)/4-ampy complex system in the presence of hydrogen peroxide. The [ O Cu III (IDA)(4-ampy) 2 ] species were detected by in-situ high-definition electrospray ionization mass spectrometry, and has been considered as the possible active species during H 2 O 2 activation catalyzed by the IDA/Cu(II)/4-ampy complex (with the molar ratio of IDA/Cu(II)/4-ampy being greater than 1:1:2). A mechanism has been proposed based on the results of electron paramagnetic resonance and density functional theory calculations. [ABSTRACT FROM AUTHOR]

Porphyrin has received increasing interest in the catalysis field due to their excellent catalytic performance, nevertheless, the development of highly efficient porphyrin catalysts is still a significant challenge. In this work, a representative of persistent free radicals (PFRs), multiwalled carbon nanotubes (MWCNTs), was innovatively employed to construct an outstanding catalytic system, hemin-MWCNTs/H 2 O 2 . The introduction of MWCNTs greatly enhanced the catalytic activity of hemin, representing about 61 times higher reaction rate constant with the dye of methylene blue (MB) as probe compound, which was attributed to more reactive oxygen species (ROS) ( OH and hemin (Fe IV O)) generation. When MWCNTs were introduced to hemin/H 2 O 2 system, the decrease of PFRs concentration in MWCNTs were observed with larger number of trapped electrons, indicating that PFRs might transfer electrons to hemin, thus speeding up the reaction rate-determining step of hemin (Fe III ) to hemin (Fe II ), resulting in enhanced production of OH and hemin (Fe IV O). This study initiates an up-to-date research domain of PFRs-enhanced catalysis, paving the avenue toward developing robust processes for the efficient generation of ROS for applications in catalysis field. [ABSTRACT FROM AUTHOR]

The design of catalytic oxidation processes with high efficiency has attracted considerable attention for a long while in environmental catalysis. In this work, a novel oxidation system, CFs-CoPc/PMS, was developed by coupling cellulosic fibers-bonded cobalt phthalocyanine (CFs-CoPc) with peroxymonosulfate (PMS). CFs-CoPc/PMS system could effectively decolorize azo dyes such as Acid Red 1 (AR1) with almost 100% decolorization efficiency in 35 min, suggesting that the CFs-CoPc/PMS system was a highly efficient oxidation process. In addition, bicarbonate ion (HCO 3 − ) was further introduced to CFs-CoPc/PMS to construct a combined system, CFs-CoPc/PMS/HCO 3 − . Remarkably, this system turned the negative effect of HCO 3 − observed in most reported Co/PMS systems into a positive one, which enhanced the AR1 decolorization with over 2-fold increase of the rate constant. The main factor responsible for the enhancement was high-valent cobalt-oxo intermediates (PcCo IV = O), which was presumably generated via the heterolytic cleavage of the PMS OO bond by CoPc-HCO 3 − complex. It is noteworthy that high-valent cobalt-oxo intermediates as the major active species is different from most reported mechanisms in Co/PMS systems, in which hydroxyl and sulfate radicals are recognized as the dominant active species. This study paves an avenue for developing highly efficient catalytic oxidation technology for wastewater remediation. [ABSTRACT FROM AUTHOR]

Peroxymonosulfate (PMS) activation has received increasing attention owing to the generation of powerful radicals for the removal of organic pollutants in the environmental catalysis field, although the development of highly efficient and environmentally benign oxidation processes has proven to be a significant challenge. In this work, an effective and stable catalyst (Fe@ACFs) has been tested for the first time for the heterogeneous activation of PMS for the removal of organic pollutants. The experimental results revealed that Fe@ACFs displayed sustained catalytic ability, and compared with the most commonly used oxidant, H 2 O 2 , the introduction of PMS contributed specifically to the activity enhancement of the catalytic system. Meanwhile, electron paramagnetic resonance (EPR) combined with two kinds of radical scavengers (methanol and tert -butyl alcohol) has been employed to confirm that hydroxyl radicals ( OH) and sulfate radicals (SO 4 − ) serve as the active species in the reaction process. Importantly, the negative effect of NaCl normally observed in hydrogen peroxide activation was turned into a positive effect at high NaCl concentrations. Furthermore, the catalyst also displayed excellent stability and reusability in these experiments, avoiding secondary contamination and being conducive to green catalysis. This work provides a new process to solve the dichotomy between efficiency and environmental benignity in PMS activation, which may find practical application for the treatment of organic pollutants in water. [ABSTRACT FROM AUTHOR]

It is of great significance for improving electron transmission performance by changing of the outer ring structure of iron phthalocyanine. Herein, 4 (pyridine-2, 3-yl) iron phthalocyanine (FepyPc), as N -rich pyridyl-iron phthalocyanine derivative, was introduced to degrade pharmaceutical contaminants. The catalytic degradation of organic pollutants with FepyPc was studied by activating peroxymonosulfate (PMS) at room temperature. The results clarified that the removal rate of carbamazepine (CBZ) was close to 100% within 60 min and the calculated apparent rate constant was about 2 times larger than FePc, which proved that FepyPc had superior performance. Four active species were identified for the degradation of CBZ, including superoxide radical (•O 2 −), singlet oxygen (1O 2), sulfate radical (SO 4 •−) and hydroxyl radical (•OH). In addition, the possible reaction mechanism was inferred in FepyPc/PMS/sunlight system for CBZ removal. Finally, the CBZ degradation pathway was proposed by using ultra-performance liquid chromatography and high definition mass spectrometry (UPLC/HDMS). This research provided a meaningful and efficient method for the elimination of pharmaceutical contaminants. [Display omitted] • N -rich pyridyl-FePc derivative with efficient PMS activation ability was prepared. • The elimination of pharmaceutical in diverse environment were illustrated. • The possible mechanism with four active species for CBZ removal was proposed. • The degradation pathway of CBZ was proposed. [ABSTRACT FROM AUTHOR]

The peroxymonosulfate-based advanced oxidation process (PMS-AOP) is widely studied as a powerful technology for organic pollutants degradation in wastewater. In this paper, an inventive one-step method utilizing potassium persulfate (KPS) as an oxidizing agent was put forward to prepare metal-free carboxyl modified graphite phase carbon nitride (g-C 3 N 4 (KPS)), which was applied to significantly activate PMS for the degradation of organic compound carbamazepine (CBZ) under solar radiation. Without strong acids and organic solvents, the process was considered green, low-cost, and facile. The characterizations showed that g-C 3 N 4 (KPS) was successfully doped with carboxyl groups on g-C 3 N 4. Besides, •OH, 1O 2 , •O 2 − and h+ were generated in the photocatalytic system of g-C 3 N 4 (KPS)/PMS. As a result, a possible CBZ photocatalytic degradation pathway was proposed. This work not only discovered a novel method of activating PMS but also offered valuable insights for the preparation of efficient metal-free catalysts for wastewater environmental governance. [Display omitted] The carboxyl-modified g-C 3 N 4 prepared by a novel one-step method could efficiently activate PMS under solar radiation. The photogenerated electron-hole pairs of g-C 3 N 4 (KPS) were effectively separated to enhance the ability of organic pollutants degradation. g-C 3 N 4 (KPS) exhibited excellent cyclability in wastewater containing a variety of anions and a wide pH range. The catalytic mechanism of g-C 3 N 4 (KPS)/PMS/solar radiation system was proposed, and •OH, 1O 2 , •O 2 −, h+ were the main active species of the catalytic system. A possible photocatalytic degradation process of CBZ was presented. [ABSTRACT FROM AUTHOR]

Thedevelopment of a pH-tolerant Fenton-like catalyst is an activeand challenging research front in the area of environmental engineering.In the present work, a novel catalyst iron−γ-aminopyridineligand (FeAPy) was prepared and immobilized on activated carbon fibers (ACFs) by a covalent bond to obtain a heterogeneous FeAPy-ACFs. FeAPy-ACFspresent a pH-tolerant microenvironment for the Fenton-like oxidationprocess, which exhibits remarkable catalytic ability across a widepH range from acidic to alkaline. At neutral pH, employing hydrogenperoxide as an oxidant, the FeAPy-ACFs showed enhanced catalytic abilityto degrade hazardous environmental pollutants Acid Red 1 (AR1) dyesand avoid secondary pollution with regard to FeAPy. FeAPy-ACFs arestable and remain efficient in repetitive test cycles with no obviousdecrease of catalytic activity. Moreover, in comparison to most reportedsupports for Fenton-like catalyst, the introduction of ACFs contributedspecifically to the activity improvement of FeAPy. Probe studies combinedwith electron paramagnetic resonance experiments were conducted toascertain the role of several reactive species (•OH, HO2•, and FeIVO) on dye decolorization. [ABSTRACT FROM AUTHOR]

[Display omitted] • The DCD acted as a "tailor" to obtain High-loading W-CN SACs; • The ESI-HDMS was used to track the structure evolution of W-CN; • The W species formed the unique single-atom "N-W-O 3 " moieties on CN; • The utilization of photo-excited carriers was improved; • W-CN exhibited excellent performance of CBZ elimination. Single-atom catalysts (SACs) have become an attractive concept in heterogeneous catalysis because of its high activity, selectivity and maximized utilization efficiency. However, constructing a high-loading SACs through conventional pyrolysis methods remains a challenge, because metal precursors usually have low thermal stability and the decrease of particle size will lead to an increase of surface energy. Herein, we used dicyandiamide to tailor the metatungstate and fix the W atoms during the thermal polymerization process, finally obtained a new kind of W-SAC (single W atoms anchored on graphitic carbon nitride, named as W-CN) with a high-loading of 11.16 wt% and a unique O, N coordination. The electrospray ionization high-definition mass spectrometry (ESI-HDMS) revealed that single W atoms were introduced into graphitic carbon nitride via the polycondense of W-containing dicyandiamide intermediate. The unique atomically dispersed N-W-O 3 moieties, which promoted the separation efficiency of photogenerated electron-hole pairs, were identified by Aberration-corrected scanning transmission electron microscopy (AC-TEM), X-ray photoelectron spectroscopy (XPS), X-ray absorption fine structure spectroscopy (XAFS) and Density functional theory (DFT) calculation. Moreover, compared to pure CN, the W-CN exhibited an enhanced catalytic performance for the oxidation of carbamazepine (CBZ) under solar light irradiation. The experiment results revealed that photogenerated holes (h+), superoxide radicals (•O 2 −), and singlet oxygen (1O 2) were the predominant active species and played an important role in eliminating emerging contaminants. This work paves a facile and efficient path toward high-loading SAC, and opens new insight into tracking SAC structure evolution. [ABSTRACT FROM AUTHOR]

[Display omitted] • Formation of active N–Co(II)–O centers by calcinating under oxidizing atmosphere. • The elimination of target pollutants in high backgrounds of complex constituents. • Heterolytic cleavage of peroxide O-O bond to form the Co(IV) = O species. • Provide a thought to prepare Co-based hybrid organic–inorganic heterogeneous catalyst. Co-based hybrid organic–inorganic heterogeneous catalyst was prepared using cobalt tetraaminophthalocyanine (CoTAPc) as precursor via simple one-pot calcination under oxidizing atmosphere, and characterized by X-ray photoelectron spectroscopy, transmission electron microscopy, X-ray absorption fine spectroscopy, etc. The results showed that the oxygen (O) atom was introduced into the Co(II)–N4 structure of CoTAPc, generating the active N–Co(II)–O centers with novel coordination environment around the ion of cobalt. This heterogeneous Co-based hybrid catalyst exhibits high catalytic activity and sufficient stability for the elimination of organic pollutants by H 2 O 2 activation, even in high backgrounds of complex constituents. Moreover, the controllable H 2 O 2 activation was achieved at relatively low H 2 O 2 dosage under mild condition. The possible mechanism of the heterolytic cleavage of O–O bond during H 2 O 2 activation was proposed, and such different cobalt coordination environment facilitated the formation of high active Co(IV) = O species. Besides, the oxidation pathway of substrates was presented according to the intermediates and the final products detected by ultra-performance liquid chromatography/high-definition mass spectrometry and gas chromatography/mass spectrometry, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • The electron transfer between g-C 3 N 4 and TiO 2 suppresses the photogenerated charge recombination. • g-C 3 N 4 extends the visible light absorption range of the composite and helps to the exposure of active sites. • The g-C 3 N 4 layer prevents the cotton support from being corroded by TiO 2. • By introducing KH550, the connection becomes easier and firmer between g-C 3 N 4 and the cotton support. In this work, a flexible photocatalytic material (TiO 2 @g-C 3 N 4 -cotton) was obtained using modified graphitic carbon nitride (g-C 3 N 4 -CONH-KH550) for the a connection between the natural cotton supports and titanium dioxide (TiO 2) successively. Under the visible light, a valid photocatalytic activity was observed in the degradation of sulfaquinoxaline (SQX) and thiamethoxam. According to the support stability tests and the UV accelerated aging tests, g-C 3 N 4 -CONH-KH550 could shelter the supports with TiO 2 from the oxidation attack by hydroxyl radicals (•OH) generated. The investigation of antibacterial activity showed efficient inactivation of both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Therefore, TiO 2 @g-C 3 N 4 -cotton showed stronger mechanical performance and much longer lifetime compared with TiO 2 @cotton. The degradation products and processes of substrates were investigated. This paper provides a new idea about the construction of an efficient and stable supported photocatalytic material. [ABSTRACT FROM AUTHOR]