“…The respective onset potentials (vs. Ag-AgCl) of the WW6 and WU6 photoanodes are 0.41 V and 0.28 V in the presence of SO 3 2– and 0.50 V and 0.48 V in the absence of SO 3 2– , respectively. This is consistent with previous reports on WO 3 -based electrodes ( Ng et al, 2012 , Gomis-Berenguer et al, 2018 , Patil and Patil, 1996 , Costa et al, 2020 , Núñez et al, 2019 ). Fig.…”
The use of antiviral drugs has surged as a result of the COVID-19 pandemic, resulting in higher concentrations of these pharmaceuticals in wastewater. The degradation efficiency of antiviral drugs in wastewater treatment plants has been reported to be too low due to their hydrophilic nature, and an additional procedure is usually necessary to degrade them completely. Photocatalysis is regarded as one of the most effective processes to degrade antiviral drugs. The present study aims at synthesizing multiphase photocatalysts by a simple calcination of industrial waste from ammonium molybdate production (
WU
photocatalysts) and its combination with WO
3
(
WW
photocatalysts). The X-ray diffraction (XRD) results confirm that the presence of multiple crystalline phases in the synthesized photocatalysts. UV-Vis diffuse reflectance spectra reveal that the synthesized multiphase photocatalysts absorb visible light up to 620 nm. Effects of calcination temperature of industrial waste (550-950°C) and WO
3
content (0-100%) on photocatalytic activity of multiphase photocatalysts (
WU
and
WW
) for efficient removal of SARS-CoV-2 antiviral drugs (lopinavir and ritonavir) in model and real wastewaters are studied. The highest
k
1
value is observed for the photocatalytic removal of ritonavir from model wastewater using
WW4
(35.64×10
–2
min
–1
). The multiphase photocatalysts exhibit 95% efficiency in the photocatalytic removal of ritonavir within 15 of visible light irradiation. In contrast, 60 min of visible light irradiation is necessary to achieve 95% efficiency in the photocatalytic removal of lopinavir. The ecotoxicity test using zebrafish (
Danio rerio
) embryos shows no toxicity for photocatalytically treated ritonavir-containing wastewater, and the contrary trend is observed for photocatalytically treated lopinavir-containing wastewater. The synthesized multiphase photocatalysts can be tested and applied for efficient degradation of other SARS-CoV-2 antiviral drugs in wastewater in the future.
“…The respective onset potentials (vs. Ag-AgCl) of the WW6 and WU6 photoanodes are 0.41 V and 0.28 V in the presence of SO 3 2– and 0.50 V and 0.48 V in the absence of SO 3 2– , respectively. This is consistent with previous reports on WO 3 -based electrodes ( Ng et al, 2012 , Gomis-Berenguer et al, 2018 , Patil and Patil, 1996 , Costa et al, 2020 , Núñez et al, 2019 ). Fig.…”
The use of antiviral drugs has surged as a result of the COVID-19 pandemic, resulting in higher concentrations of these pharmaceuticals in wastewater. The degradation efficiency of antiviral drugs in wastewater treatment plants has been reported to be too low due to their hydrophilic nature, and an additional procedure is usually necessary to degrade them completely. Photocatalysis is regarded as one of the most effective processes to degrade antiviral drugs. The present study aims at synthesizing multiphase photocatalysts by a simple calcination of industrial waste from ammonium molybdate production (
WU
photocatalysts) and its combination with WO
3
(
WW
photocatalysts). The X-ray diffraction (XRD) results confirm that the presence of multiple crystalline phases in the synthesized photocatalysts. UV-Vis diffuse reflectance spectra reveal that the synthesized multiphase photocatalysts absorb visible light up to 620 nm. Effects of calcination temperature of industrial waste (550-950°C) and WO
3
content (0-100%) on photocatalytic activity of multiphase photocatalysts (
WU
and
WW
) for efficient removal of SARS-CoV-2 antiviral drugs (lopinavir and ritonavir) in model and real wastewaters are studied. The highest
k
1
value is observed for the photocatalytic removal of ritonavir from model wastewater using
WW4
(35.64×10
–2
min
–1
). The multiphase photocatalysts exhibit 95% efficiency in the photocatalytic removal of ritonavir within 15 of visible light irradiation. In contrast, 60 min of visible light irradiation is necessary to achieve 95% efficiency in the photocatalytic removal of lopinavir. The ecotoxicity test using zebrafish (
Danio rerio
) embryos shows no toxicity for photocatalytically treated ritonavir-containing wastewater, and the contrary trend is observed for photocatalytically treated lopinavir-containing wastewater. The synthesized multiphase photocatalysts can be tested and applied for efficient degradation of other SARS-CoV-2 antiviral drugs in wastewater in the future.
“…Therefore, the E fb value of the semiconductor gives us the position of one of the two bands, whereas the E bg value indicates the position of the other. 77 Here, the E fb values were determined using a similar methodology to that earlier adopted by our research group 76,78 , the Butler-Gärtner model (ie, the variation of the current square). This model assumes that the photocurrent (I ph ) is observed only when the electrode potential is more positive than the semiconductor flat band potential (ie, when E > E fb and I ph > 0).…”
Summary
In this article, we report a solar cell prepared with p‐type cuprous oxide (Cu2O) and n‐type gamma‐tungsten oxide (γ‐WO3) films combined by an redox electrolyte in a configuration similar to that used in dye‐sensitized solar cells. Cu2O films were prepared by the electrochemical method in three different pH conditions. X‐ray diffraction patterns revealed that the Cu2O films presented a crystalline phase with cubic structure after deposition, whereas the n‐type γ‐WO3 film was prepared by the drop‐casting method. Optical analyses showed that both oxide films absorb visible light. After the photoelectrochemical characterization of the films, solar cells configured like a “sandwich” (Cu2O/electrolyte/γ‐WO3) were assembled and investigated under irradiation of 100 mW cm−2. The solar cell with I−/I3− redox pair showed better results than that prepared with polysulfide K2S/Sn2− electrolyte. For each solar cell, the investigated parameters were short‐circuit current density, open‐circuit voltage, fill factor, maximum power, and cell efficiency. The method proposed here can be considered new, promising, and simple for the preparation of solar cells with a p–n junction.
“…The potential of the flat band is referred to as the flat-band potential ( E FB ) and corresponds to the CB of the photocatalyst ( E CB ). The difference between E CB and E FB depends on the effective density of charges ( N D ) and density of states in the CB ( N CB ) as follows ECB−EFB=kTelnNnormalDNCBNCB=2true(2πmeitalickTh2true)3/2where k is the Boltzmann constant, T is the temperature, e is the charge of electron, m e is the effective mass of electron in the semiconductor, and h is the Planck constant.…”
Section: Introductionmentioning
confidence: 99%
“…22 The potential of the flat band is referred to as the flat-band potential (E FB ) and corresponds to the CB of the photocatalyst (E CB ). The difference between E CB and E FB depends on the effective density of charges (N D ) and density of states in the CB (N CB ) as follows 23 where k is the Boltzmann constant, T is the temperature, e is the charge of electron, m e is the effective mass of electron in the semiconductor, and h is the Planck constant. Several (photo)electrochemical methods can be employed for the determination of the flat-band potential in semiconducting photocatalysts.…”
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