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FeWO4 was synthesized by a simple solvothermal method. The band structure of FeWO4 was investigated on the basis of density functional theory calculations. The FeWO4 photocatalyst showed lower photocatalytic activity for the degradation of doxycycline hydrochloride under visible light irradiation. Kinetic studies using radical scavenger technologies suggested that hydroxyl radicals were the dominant photo-oxidants. In order to enhance the photocatalytic activity of FeWO4, FeWO4 was used to activate peroxymonosulfate to degrade doxycycline hydrochloride under visible light irradiation. The influences of the peroxymonosulfate dosage, doxycycline hydrochloride concentration, inorganic anions, natural organic matter and pH value on activating peroxymonosulfate to degrade doxycycline hydrochloride were investigated in detail. The mechanism of FeWO4 activating peroxymonosulfate was proposed and proved by radical quenching experiments, electron spin resonance analysis, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy, transient photocurrent responses and cyclic voltammetry. It can be found that the combined activation effects of photo-generated electrons and transition metals on peroxymonosulfate to produce sulfate radicals could enhance the degradation efficiency obviously. [ABSTRACT FROM AUTHOR]

MIL-53Fe was prepared by a simple solvothermal method, and the MIL-53Fe photocatalysts showed low photocatalytic activity for the degradation of tetracycline hydrochloride under visible light irradiation. After combination with TiO2, the photocatalytic activity of MIL-53Fe was enhanced obviously. The enhanced photocatalytic activity of the MIL-53Fe@TiO2 photocatalysts could be attributed to the effective separation of the photogenerated e−/h+ pairs. In order to further enhance the degradation efficiency of MIL-53Fe@TiO2, it was used to activate peroxymonosulfate to degrade tetracycline hydrochloride. The influencing factors on the activation of peroxymonosulfate to degrade tetracycline hydrochloride were investigated in detail. The mechanism of MIL-53Fe@TiO2 activation of peroxymonosulfate was investigated by radical quenching experiments, which proved that holes and sulfate radicals controlled the degradation of tetracycline hydrochloride. Cycle experiments showed that the photodegradation efficiency did not change obviously after the catalyst was recycled three times. This study provided a new way that the synergetic effect of photocatalysis and peroxymonosulfate activation by transition metal was used for efficient photocatalytic degradation in the field of antibiotic removal, hoping to provide new ideas for the development of metal–organic frameworks. [ABSTRACT FROM AUTHOR]

Fe2(MoO4)3 photocatalysts were synthesized by a simple hydrothermal method. Fe2(MoO4)3 photocatalysts showed lower photocatalytic activity for the degradation of methylene blue under visible light irradiation. After compositing with g-C3N4, the photocatalytic activity of Fe2(MoO4)3 was enhanced obviously. The enhanced photocatalytic activity of the g-C3N4/Fe2(MoO4)3 photocatalysts could be attributed to the effective separation of the photogenerated e−/h+ pairs. In order to further enhance the degradation efficiency of g-C3N4/Fe2(MoO4)3, g-C3N4/Fe2(MoO4)3 was used to double activate peroxymonosulfate to degrade methylene blue. The influences of peroxymonosulfate dosage, pH value, inorganic anions and methylene blue concentration on double activating peroxymonosulfate to degrade methylene blue were investigated in detail. The mechanism of g-C3N4/Fe2(MoO4)3 double activating peroxymonosulfate was proved by radical quenching experiments, which proved that SO4˙− dominated the degradation of methylene blue. [ABSTRACT FROM AUTHOR]

Bi2WO6/Bi2MoO6 heterostructured photocatalys had been synthesized by a refluxing method. And the photocatalytic activity of Bi2WO6/Bi2MoO6 heterostructured photocatalysts was better than Bi2WO6. The enhancement in photocatalysis activity belonged to the match of energy level between the Bi2MoO6 and Bi2WO6. In order to further enhance the photocatalytic activity of Bi2WO6/Bi2MoO6, Bi2WO6/Bi2MoO6 was used to activate peroxymonosulfate to photodegradate methylene blue. The mechanism of activating peroxymonosulfate was proved by radical quenching experiment which revealed that sulfate radicals governed the removal of methylene blue. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co/Mn-MOF-74@g-C 3 N 4 photocatalyst was synthesized by solvothermal method. • Peroxymonosulfate was activated by photogenerated e−, Co and Mn. • SO 4 •−, 1O 2 , •O 2 and h+ mainly control the degradation of doxycycline hydrochloride. A new Z-type heterojunction photocatalytic material Co/Mn-MOF-74@g-C 3 N 4 was prepared by a simple solvothermal method. Co/Mn-MOF-74@g-C 3 N 4 was found to have a much higher photocatalytic activity than simple Co/Mn-MOF-74 due to the formation of Z-scheme heterojunction, which inhibited the recombination of photogenerated electrons and holes. Photocatalytic activity was further enhanced by activating peroxymonosulfate with Co/Mn-MOF-74@g-C 3 N 4. The removal rate of doxycycline hydrochlorid was 94 % within 60 min after adding 0.5 mmol peroxymonosulfate in the system. Furthermore, XPS, EPR and radical quenching experiments were used to demonstrate the electron transfer of Co/Mn (II) and Co/Mn (III) in Co/Mn-MOF-74 and peroxymonosulfate activation mechanism for enhanced photocatalytic performance. The possible vulnerable sites and degradation pathways of doxycycline hydrochlorid by Co/Mn-MOF-74@g-C 3 N 4 were studied by density functional theory and UPLC-MS. Toxicity Estimation Software predicted that the degradation processes of doxycycline hydrochloride could gradually reduce toxicity. This study could provide an efficient and green method for the subsequent treatment of antibiotic wastewater. [ABSTRACT FROM AUTHOR]

The MIL-53Fe@g-C 3 N 4 samples were prepared by solvothermal method and recorded as CM-x. The potocatalytic activity of the MIL-53Fe@g-C 3 N 4 was significantly higher than MIL-53Fe, and it might be due to the successfully constructed heterojunction promoting the migration and separation effciency of photo-generated electron and hole pairs. In order to further enhance the potocatalytic activity of the MIL-53Fe@g-C 3 N 4 , peroxymonosulfate was introduced into the MIL-53Fe@g-C 3 N 4 /Vis system, and the peroxymonosulfate could be simultaneously activated by photogenerated electron and iron to form sulfate radical under visible light irradiation. Therefore, the degradation efficiency of oxytetracycline hydrochloride was enhanced obviously. Meantime, the effects of peroxymonosulfate dosage, oxytetracycline hydrochloride concentration, temperature and pH on the degradation efficiency of oxytetracycline hydrochloride were studied systematically. Meanwhile, the free radical catching experiments and electron spin resonance analysis confirmed that the main active substances were sulfate radical and hole. Finally, the mechanism and possible degradation pathways of MIL-53Fe@g-C 3 N 4 activating peroxymonosulfate to degrade oxytetracycline hydrochloride were proposed. [Display omitted] • MIL-53Fe@g-C 3 N 4 photocatalysts was synthesized by solvothermal method. • Peroxymonosulfate was activated by photogenerated e− and Fe. • The SO 4 •− and •OH mainly contributed to oxytetracycline hydrochloride degradation. [ABSTRACT FROM AUTHOR]

MFeO3 (M = La or Bi) photocatalysts were synthesized via a sol–gel process. The MFeO3 photocatalysts showed lower photocatalytic activity for the degradation of doxycycline hydrochloride under visible light irradiation. After the MFeO3 nanoparticles were loaded in the channels of SBA-15, the photocatalytic activity of MFeO3/SBA-15 was enhanced by nine and two times compared to that of pure LaFeO3 and BiFeO3, respectively. The enhanced photocatalytic activity of the MFeO3/SBA-15 photocatalysts could be attributed to their larger surface areas. In order to further enhance the degradation efficiency for doxycycline hydrochloride, MFeO3/SBA-15 was used to activate peroxymonosulfate; the Vis/MFeO3/SBA-15/PMS system showed the best activity in the degradation of doxycycline hydrochloride, which was two and three times higher than that of the Vis/LaFeO3/SBA-15 and Vis/BiFeO3/SBA-15 systems, respectively. The influences of PMS dosage, pH value, temperature, natural organic matter, inorganic anions and doxycycline hydrochloride concentration on the degradation rates were investigated in detail. The PMS activation mechanisms induced by MFeO3/SBA-15 were examined by radical quenching, electron paramagnetic resonance tracing methods and photoluminescence spectral characterization. It was found that the photogenerated e−/h+ and the Fe(III)/Fe(II) redox pairs on the surface of MFeO3/SBA-15 could synergistically activate PMS to produce sulfate radical, and the sulfate radical was the main active substance. [ABSTRACT FROM AUTHOR]

Bi2MoO6 nanoflakes are synthesized via a normal hydrothermal method. Bi2MoO6 photocatalysts show lower photocatalytic activity for the degradation of methylene blue under visible light irradiation. In order to further enhance the degradation efficiency, Bi2MoO6 is used to activate the peroxymonosulfate for the degradation of methylene blue under visible light. Bi2MoO6 nanoflakes show excellent degradation efficiency in the Bi2MoO6/Vis/peroxymonosulfate (PMS) system. Moreover, the influences of PMS dosage, pH value, and inorganic anions on photodegradation are evaluated. The mechanism of activating peroxymonosulfate is proved by radical quenching experiment, which reveals that sulfate radicals govern the removal of methylene blue. [ABSTRACT FROM AUTHOR]