Construction of an S-Scheme Ag₂MoO₄/ZnFe₂O₄ Nanofiber Heterojunction for Enhanced Photoelectrocatalytic Activity under Visible Light Irradiation

Abstract

The removal of organic dyes and pathogenic bacteria from contaminated water remains a significant challenge. In the present study, S-type heterojunction Ag2MoO4/ZnFe2O4 (AMO/ZFO) composite nanofibers were synthesized by electrospinning and co-precipitation and fabricated into photoanodes. It is found that the constructed S-type heterojunction of AMO/ZFO composites effectively inhibits the recombination of photogenerated carriers, in addition to the benefits of more exposed active sites and a greater specific surface area. When several properties are improved, AMO/ZFO composites exhibit excellent photoelectrocatalytic performance. The results demonstrate that under visible light irradiation, the photoelectrocatalytic degradation rate of AMO/ZFO-3 to methylene blue reached 76.2% within 50 min, and the killing rate of Salmonella was 83.6% within 80 min. The enhanced photoelectrocatalytic activity was due to the synergy of both electrochemical and photocatalytic effects. More importantly, after four testing cycles, AMO/ZFO-3 still has a better ability to kill pathogenic bacteria and degrade organic dyes due to its high stability. This work provides a feasible method for oxidizing organic dyes and pathogenic bacteria.

MOF-Derived Hollow Spheres of MIL-100(Fe)-NH2(20) with Well-Developed Hierarchical Mesoporous and Uniform Distribution of Fe and N Active Phases for the Photocatalytic Removal of Organic Dyes

“…Obviously, the intensity of the PL emission follows the order MIL-100­(Fe) > MIL-100­(Fe)-NH 2 (5) > MIL-100­(Fe)-NH 2 (7) > MIL-100­(Fe)-NH 2 (15) > MIL-100­(Fe)-NH 2 (10) > MIL-100­(Fe)-NH 2 (20). A lower PL intensity indicates a higher separation efficiency between photogenerated electrons and holes . Hence, it was verified that the amino-modified MIL-100­(Fe)-NH 2 ( x ) can effectively bate the recombination of photogenerated carriers, and the effect is the clearest in MIL-100­(Fe)-NH 2 (20).…”

“…A lower PL intensity indicates a higher separation efficiency between photogenerated electrons and holes. 57 Hence, it was verified that the amino-modified MIL-100(Fe)-NH 2 (x) can effectively bate the recombination of photogenerated carriers, and the effect is the clearest in MIL-100(Fe)-NH 2 (20).…”

Novel electrospun bead-like Ag2MoO4 nanofibers coated on Ni foam for visible light-driven heterogeneous photocatalysis and high-performance supercapacitor electrodes

“…The sloping fluctuation in potential in discharge curves displayed their pseudocapacitive character, which may be attributed to the faradaic reactions at the electrolyte–electrode interface. 63,65 Using eqn (11), where C s (F g −1 ), I / m (A g −1 ), Δ t (s), and Δ V (V) are the specific capacitance, current density, discharge time, and potential window, respectively, 77 MoO 3 @Ni foam had C s values of 1220, 1040, 988, 855, 800 and 733 F g −1 at current densities of 1, 3, 5, 7, 10 and 15 A g −1 , while Ag 2 MoO 4 @Ni foam had C s values of 1695, 1580, 1255, 1057, 977 and 933 F g −1 at the same current densities.The calculated C s values in this work were compared with previously reported values (see Table 2). The difference in the results may be related to the variety of morphology, specific surface area, preparation method, number of electroactive sites, phase purity and conductivity of the nanoparticles.…”

“…The mass loading ratio between the positive and negative electrodes was calculated using eqn (13), with a value of 0.317.where Δ V − (Δ V + ) and C − ( C + ) refer to the potential and specific capacitance of the negative (positive) electrode, respectively. 25 Eqn (14) can be used to determine the specific capacitance of the electrode from CV curves: 65 where m (g), Δ V (V), and s (V s −1 ) are the integrated area in the CV curve, active material mass, working potential window, and scan rate, respectively. To assess the operating voltage of the ASC device, a conventional three-electrode setup was employed to record the CV curve of the AC and Ag 2 MoO 4 @Ni foam electrodes at an 80 mV s −1 scan rate (Fig.…”

Construction of Z-Scheme Ag2MoO4/ZnWO4 Heterojunctions for Photocatalytically Removing Pollutants

“…Multiple measures have been therefore used to improve the photocatalytic activity of ZWO (especially integrated with other semiconductors to form heterojunctions). − AMO is one of the important silver-based semiconductors, attracting considerable attention from researchers due to its promising photocatalytic capability, antimicrobial activity, and good photoluminescence property. , Furthermore, AMO also exhibits a synergistic flexo-photocatalytic degradation of organic pollutants under both simulated sunlight and ultrasonic irradiation . Although AMO has been shown to be promising in the photocatalytic removal of environmental pollutants, its photocatalytic activity still needs to be further improved via various avenues. − …”