Photocatalytic Degradation Of Rhodamine B Research Articles

Preparation of TiO2-activated kaolinite composite for photocatalytic degradation of rhodamine B dye

ABSTRACT. Rhodamine B (RhB) is one of the prominent dyes discovered to be carcinogenic and mutagenic substance present in the ecosystem. Alteration of the characteristics of TiO2 through modification with clay influences the behavior of some organic molecules at its surface, and thus its photocatalytic properties. This study investigates the photocatalytic degradation of RhB using TiO2-activated kaolinite composite (TiO2-AKC). TiO2-AKC was prepared in absolute ethanol and characterized using SEM, EDX, TEM, BET and FTIR. The photodegradation of RhB using TiO2-AKC at room temperature under visible-light was studied at various time intervals and the concentration of RhB was monitored using Ultraviolet-Visible spectrophotometer. Characterisation of TiO2-AKC revealed an adequate distribution of TiO2 over the AKC surface, with an enhanced surface area (TiO2-AKC 808 m2g-1, TiO2 50.0 m2g-1, AKC 20.6 m2g-1) necessary for effective degradation. The degradation was efficient in TiO2-AKC than in sole TiO2 resulting in 99.51% and 88.35%, respectively. The experimental data was analysed using zeroth and first order kinetics, parabolic diffusion, and modified Freundlich model. The degradation kinetics conforms to first order kinetics in TiO2-AKC and sole TiO2. The mechanism of the degradation using TiO2-AKC fit into modified Freundlich model and parabolic diffusion model while sole TiO2 was best described by parabolic diffusion model.
 
 KEY WORDS: Kaolin, Kinetics, Organic dyes, Photodegradation, Pollutants, Titanium(IV) oxide
 Bull. Chem. Soc. Ethiop. 2022, 36(1), 13-24. 
 DOI: https://dx.doi.org/10.4314/bcse.v36i1.2

Synthesis, crystal structure and photocatalytic properties of two bismuth(III) complexes with different N-containing heterocycles

Two novel bismuth(III) complexes of the formulae (2-HMI)4[Bi2Cl10] (1) and {(Hphen)[BiCl4]}n (2) (2-MI = 2-methylimidazole, Hphen = 1,10-phenanthroline) were synthesized. The complexes were characterized by elemental analyses, X-ray diffraction, Fourier transform infrared spectra and thermogravimetry analysis. The X-ray crystallographic investigation reveals that 1 is ionic compound built of 2-methylimidazolium cations and binuclear metalate anions, [Bi2Cl10]4–. 2 is a coordination polymer, and its asymmetric structural units are connected by one Bi3+ ion, four Cl– ions and one disordered and protonized Hphen+ cation. In addition, the photocatalytic activities of 1 and 2 towards the degradations of Rhodamine B (RhB) and methylene blue (MB) were explored, and the mechanism of the photocatalytic degradation was also discussed. The results show that 1 and 2 are good candidates for photocatalytic degradation of RhB and 2 is also a good candidate for photocatalytic degradation of MB.

Preparation of a novel composite photocatalyst BiOBr/ZIF-67 for enhanced visible-light photocatalytic degradation of RhB

In the preparation process of a novel composite photocatalyst BiOBr/ZIF-67, BiOBr prepared by one-step hydrothermal synthesis was used as the base material, and ZIF-67 was attached to the surface of BiOBr by the one-pot method; a series of BiOBr/ZIF-67 composite photocatalysts were prepared by changing the ratio of ZIF-67. Through X-ray diffraction (XRD) and other characterization methods, the prepared composites were systematically analyzed, the visible-light photocatalytic activity of which for the degradation of Rhodamine B (RhB) was studied, and a possible photocatalytic mechanism was proposed. It can be concluded from the experiment that BiOBr/ZIF-67(30%) with the best photocatalytic activity could degrade 95.2% of RhB, which is 50% higher than pure BiOBr. The prepared BiOBr/ZIF-67 was inferred to be a direct Z-Scheme heterojunction photocatalyst, which possessed intimately contacted interface and well-aligned straddling energy-band structures. In this visible-light heterojunction photocatalysts, ZIF-67 increased the specific surface area of composites, which was propitious to bring improved photocatalytic performance.

Fabrication of Zn-Ti layered double oxide nanosheets with ZnO/ZnTiO3 heterojunction for enhanced photocatalytic degradation of MO, RhB and MB

Zn-Ti layered double oxide (LDO) nanosheets were synthesized by a simple co-precipitation-calcination process for the enhanced photocatalytic degradation of methyl orange (MO), rhodamine B (RhB) and methylene blue (MB). ZnTi-LDOs nanosheets present higher photocatalytic efficiency for MO, RhB and MB removal, which is 5.4, 4.4 and 6.7 times of that of Zn-Ti layered double hydroxide (LDH), respectively. The photocatalytic activity of synthesized ZnTi-LDOs is greatly affected by the mole ratio of Zn/Ti, calcination temperature and pH value. It is found that the formation of ZnO/ZnTiO3 heterojunction in ZnTi-LDOs could effectively accelerate the rapid separation of charge carriers, and thus enhance the photocatalytic activity via enlarging the photoresponse range. The possible charge transfer mechanism for photocatalytic degradation of organic dyes by ZnTi-LDOs was proposed based on the active species test and UV–Vis diffuse reflectance spectra. The results of active species trapping experiments showed that ‧OH, ‧O2−, h+, e− all had effect on the degradation of RhB, and ‧OH played a major role. This study provides a new insight for the photocatalytic degradation of organic pollutants from wastewater by ZnTi-LDOs.

Effect of experimental parameters on photocatalytic degradation efficiency of TiO2 nanoparticles synthesized by electrochemical method towards Rhodamine B dye solution under natural sunlight.

In this study, ~ 40nm anatase TiO2 nanoparticles were successfully prepared by a simple electrochemical method by using succinic acid as a non-ammonia-based electrolyte solution and titanium sheets as electrodes. The effect of experimental parameters such as conductivity (2-12 mS/cm), pH of the initial solution (5-9), current applied (0.05-2 A), and reaction time (1-4h) on catalyst productivity has been investigated. The analysis shows that at an optimum conductivity of 8 mS/cm and pH 7, an increase in applied current and reaction time maximizes the productivity of TiO2 nanoparticles. The obtained catalyst was used for photocatalytic degradation of rhodamine B (RhB) under natural sunlight irradiation. The effect of experimental parameters on photocatalytic degradation has also been studied. The result displayed that degradation efficiency was enhanced by ~ 3 times in the alkaline region compared to the normal pH condition and increased with an increase in catalyst loading and decreased with the initial concentration of RhB dye. Investigation of the photocatalytic mechanism by radical trapping experiments showed that RhB photocatalytic degradation was mainly dominated by hole and superoxide radicals, whereas hydroxyl radical plays a minor role. Moreover, the catalyst reusability analysis revealed good stability and showed excellent degradation up to four consecutive cycles with nearly negligible loss of photocatalytic efficiency. Thus, the present work offers a new opportunity in terms of maximization of productivity as well as sunlight-driven photocatalytic activity of the catalyst for their industrial application.

Self-assembling of 3D layered flower architecture of BiOI modified MgCr2O4 nanosphere for wider spectrum visible-light photocatalytic degradation of rhodamine B and malachite green: Mechanism, pathway, reactive sites and toxicity prediction

In this study, 3D BiOI nanoparticle (BOI NPs) modified MgCr2O4 nanoparticle (MCO NPs) was fabricated by simple sonochemical and coprecipitation method for the enhanced photocatalytic activity. The morphological structure of the MgCr2O4–BiOI nanocomposite (MCO-BOI NCs) was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–visible diffuse reflectance spectroscopy (DRS), electron impedance spectroscopy (EIS) and photo luminescence (PL). The lower in the PL intensity and small arc in EIS for NCs shows the effective charge separation and lower in rate of recombination of charge carriers in NCs than the pure MCO and BOI NPs. The degradation efficiency of Rhodamine B (RhB) and malachite green (MG) by MCO-BOI NCs was found to be 99.5% and 98.2% receptivity. In addition, the photocatalytic degradation of RhB and MG was studied under various environmental parameters (different pH, varying the concentration of NCs and dyes) and response surface (RSM) plot was performed. The complete mineralization of RhB and MG by MCO-BOI NCs was determined by TOC. In addition, the photocatalytic degradation pathway was elucidated based on GC-MS results and Fukui function. In addition, the toxicity of intermediate formed during the degradation of RhB and MG was predicted by ECOSAR. The present work highlights the application of MCO-BOI NCs in environmental remediation for toxic pollutant removal.

Carbon nitride coupled with Ti3C2-Mxene derived amorphous Ti-peroxo heterojunction for photocatalytic degradation of rhodamine B and tetracycline

Exploring the solar-driven photocatalyst for antibiotic and dye degradation has been confronted with a great challenge. In this study, a novel and original photocatalyst derived from the g-C3N4/amorphous Ti-peroxo complexes (CATC) heterojunction was successfully synthesized towards Rhodamine B (RhB) and tetracycline (TC) degradation under visible light irradiation (λ>420 nm). Based on the special photocatalytic activity, Ti3C2-Mxene acted as the starting precursor of amorphous Ti-peroxo complexes via one-step H2O2 oxidation route. Multiple characterization techniques were applied to explore the crystal structure, element composition, and photoelectrochemical property of photocatalyst. As expected, the modified photocatalyst possessed a favorable photocatalytic performance towards the preferable reaction rate for RhB (0.0483 min−1) and TC (0.0208 min−1) degradations, which were 16.65 times and 69.3 times higher than that of pure g-C3N4 (CN) material, profiting from the generated direct Z-scheme heterojunction with favorable redox capacity. Here, h+,∙O2- and ∙OH were verified as typical active radicals for RhB and TC degradation through free radical quenching experiments and electron spin resonance characterization. Degradation intermediate products were also confirmed by high performance liquid chromatography–mass spectrometer (HPLC-MS). The effects of initial pH and ionic strength on RhB and TC photocatalytic degradation performances were discussed. In addition, a preferable reusability and stability performance ensured the modification photocatalyst had a great application potential in wastewater treatment. This study provided a unique avenue through one-step method for the construction of g-C3N4 and Mxene based photocatalyst towards the degradation of antibiotics and dyes from wastewater.

In-situ construction of Bi2WO6/ZnWO4 heterojunctions with enhanced photocatalytic performance toward RhB degradation

In this work, Bi2WO6/ZnWO4 heterojunctions were in-situ constructed through a hydrothermal method. Surface photovoltage spectrometer (SPS) results illustrate that Bi2WO6/ZnWO4 heterojunctions exhibit higher separation rate of photogenerated carriers than ZnWO4, thereby resulting in the significantly enhanced photocatalytic performance. Photocatalytic activities of the samples were evaluated by degradation of rhodamine B (RhB), the results reveal that Bi2WO6/ ZnWO4 heterojunctions hold higher photocatalytic activities than that of ZnWO4. The trapping experiments display that •O2– radicals play an important role in photocatalytic degradation of RhB.

Photocatalytic degradation of rhodamine-B by visible light assisted peroxymonosulfate activation using the Z-scheme MIL-100(Fe)/Bi2S3 composite: a combined experimental and theoretical approach

MIL-100(Fe)/Bi2S3 has excellent activity towards RhB degradation.

The significance of enhanced photocatalytic degradation of RhB on the synthesis, characterization, and effects of Ag doped CdS-WO2 Nano composites

A simple and sealing agent-free hydrothermal approach was used to fabricate the very modest Ag/CdSWO2 Nano composite in this article. Powder X-ray diffraction (XRD) and UV-vis diffuse reflectance (DRS) spectroscopy was used to characterise the synthesized Ag loaded CdS-WO2 Nano composite. Under visible light irradiation (VLI), the photocatalytic activity of synthesized photocatalysts was tested for the photodegradation of rhodamine B (RhB). pH, catalyst dose, oxidant dose, and irradiation time were the parameters employed to optimise the photocatalyst. A plausible reaction mechanism for improving Ag/CdS-WO2 photocatalytic activity has been postulated based on this. As a result, we have an inclination to assume that it could be a promising material for photodegradation of organic contaminants in wastewater.

Z-scheme WO3/PANI heterojunctions with enhanced photocatalytic activity under visible light: A depth experimental and DFT studies

A WO3@PANI heterojunction photocatalyst with a various mass ratio of polyaniline to WO3 was obtained via the in situ oxidative deposition polymerization of aniline monomer in the presence of WO3 powder. The characterization of WO3@PANI composites was carried via X-ray diffraction (XRD), scanning electron microscopy (SEM-EDS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible diffuse reflection spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL). The photocatalytic efficiency of WO3@PANI photocatalysts was assessed by following the decomposition of the Rhodamine B (RhB) dye under visible light irradiation (λ >420 nm). The results evidenced the high efficiency of the WO3@PANI (0.5 wt %) nanocomposite in the photocatalytic degradation of RhB (90% within 120 min) under visible light irradiation 3.6 times compared to pure WO3. The synergistic effect between PANI and WO3 is the reason for the increased photogenerated carrier separation. The superior photocatalytic performance of the WO3@PANI catalyst was ascribed to the increased visible light in the visible range and the efficient charge carrier separation. Furthermore, the Density Functional Theory study (DFT) of WO3@PANI was performed at the molecular level, to find its internal nature for the tuning of photocatalytic efficiency. The DFT results indicated that the chemical bonds connected the solid-solid contact interfaces between WO3 and PANI. Finally, a plausible photocatalytic mechanism of WO3@PANI (0.5 wt %) performance under visible light illumination is suggested to guide additional photocatalytic activity development.

The efficacy of samarium loaded titanium dioxide (Sm:TiO2) for enhanced photocatalytic removal of rhodamine B dye in natural sunlight exposure

The photolysis method was used to successfully synthesize nanoparticles of pure TiO2 and TiO2-doped with 1,3 and 5% Sm3+ for degrading Rhodamine B (RhB) dye under sunlight. The nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscope-energy dispersive x-ray (FESEM-EDX), X-photoelectron spectrum (XPS), Raman spectrum, and UV-Visible spectrum (UV–Vis). The results from XRD and Raman showed the formation of anatase phase for prepared and doped TiO2. According to the Debye Scherrer equation, particle size decreased as Sm3+ concentration increased, reaching 4.56 nm at 5% Sm:TiO2. For the synthesized material, FE-SEM revealed a spherical agglomeration. The XPS spectrum revealed that 1% Sm:TiO2 was successfully doped, while the UV-Vis spectrum revealed that the energy gap decreased as the concentration of Sm3+ increased. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronopotentiometry were used to examine the electrochemical characteristics of pure and Sm:TiO2 under dark and light conditions (CP). The results show that the catalyst behaves as a pseudocapacitor when the Sm3+ ratio rises, as does the conductivity. The HPLC, LC/Mass, and GC/Mass were used to determine the products and photodegradation mechanism. The production of two isomer intermediates was detected in the data (EER and DR...…). Under direct sunlight, the photocatalytic degradation of RhB using%5 Sm:TiO2 was adjusted by varying pH, catalyst dosage, dye dosage, and temperature. After 120 min, the decreasing efficiency had reached 89%.

Sun/UV-light driven photocatalytic degradation of rhodamine B dye by Zn doped CdS nanostructures as photocatalyst

The optical and electronic properties of semiconducting materials are modified by the doping of suitable elements. Pure and Zn doped (1%, 3%, 5% and 7%) CdS nanostructures are synthesized by facile, one-pot solvothermal method. The synthesized materials are characterized using different characterization techniques. The XRD results revealed that the synthesized nanostructures have both, cubic and hexagonal crystalline phases. The optical band gap is increased with the increase of Zn content in the CdS matrix. The change in absorption and emission features with doping has made the doped materials suitable for photocatalytic applications under sun light and ultra-violet (UV) irradiation. The pure and Zn doped CdS nanostructures are used for photodegradation of rhodamine B (RhB) dye under UV and sun light irradiation. The Zn (3%) doped CdS nanostructures show better photocatalytic degradation (93%) of RhB under sun light irradiation. It could be due to the combined effects of the shifting in energy levels and change in shape and size of the nanostructures with doping.

One-pot synthesis of SnS2/In2S3 heterostructures for efficient photocatalysis

The exploration of effective and stable photocatalysts driven by visible light to eliminate organic pollutants is very important to environmental remediation. In this work, a simple one-pot hydrothermal method was used to successfully prepare a series of type II SnS2/In2S3 heterojunction photocatalysts. The type II heterostructure is very effective in facilitating the separation of photogenerated electron-hole pairs. Therefore, the prepared SnS2/In2S3 heterostructuresexhibited significantly improved photocatalytic performance for the decomposition of organic pollutants, including rhodamine B (RhB) and tetracycline (TC), under visible light illumination. The optimal kinetic constants of photocatalytic degradation of RhB by SnS2/In2S3 are 99.2 times and 15.3 times of the original SnS2 and In2S3, respectively. Besides, the optimal kinetic constants of SnS2/In2S3 for photocatalytic degradation of TC are 118.8 times and 12.8 times of the original SnS2 and In2S3, respectively. The radical capture experiments and electron spin resonance results indicate that ·O2– is the main active substance in the reaction system, with h+ and ·OH playing auxiliary roles, while further demonstrating the charge transfer mechanism of type II heterojunction. A new insight into the rational design and construction of efficient and stable metal sulfide-based heterojunction photocatalysts will be provided by this work.

Direct Z-scheme-based novel cobalt nickel tungstate/graphitic carbon nitride composite: Enhanced photocatalytic degradation of organic pollutants and oxidation of benzyl alcohol

Designing a photocatalyst with strong redox ability and broad absorption of visible light is challenging in the field of photocatalysis. In this study, a series of novel Z-scheme-based Co x Ni 1−x WO 4 /g-C 3 N 4 (x = 0, 0.2, 0.5, 0.8 and 1) photocatalysts are synthesized with a view to increasing their redox abilities and improve their photocatalytic activities under broad absorption of visible light. The physicochemical properties are investigated, and the data show that an intimate stable heterojunction is formed between the bimetallic tungstate (CoNiWO 4 ) and g-C 3 N 4 (g-CN). Bifunctional properties of the synthesized catalysts are assayed by studying the decomposition of rhodamine B (RhB), bisphenol A (BPA), and selective conversion of benzyl alcohol (BA) to benzaldehyde (BDA). The composite material containing 1:1 molar ratio of Co/Ni shows the highest activity towards the degradation of RhB (99.8%) and BPA (99.32%), and the conversion of BA to BDA (86.96%), each at 1 g/ L -dose. The well-matched band structure between CoNiWO 4 and g-CN facilitates the formation of a Z-scheme charge transfer path, which prolongs the life time of the photoinduced charge carriers with high redox power, thus enhancing the photocatalytic activity. An intensive study of the mechanism proves that the degradation is driven by the hydroxyl ( • OH) and superoxide ( • O 2 - ) radicals, indicating that CoNiWO 4 /g-CN follows the Z-scheme charge transfer pathway. The current study has shown the superior photocatalytic activity among all tungstate-based hybrid photocatalytic materials for the degradation of complex organic pollutants, and selective transformation of BA to BDA. The findings in this study provide a new direction to the development of an efficient direct Z-scheme Co-Ni bimetallic tungstate-based photocatalyst for several redox reactions, especially mineralization of recalcitrant aqueous organic compounds. • A novel direct Z-scheme-based CoNiWO 4 /g-CN heterojunction is synthesized. • Photocatalytic degradation of RhB and BPA, and oxidation of BA are investigated. • Material with 1:1 Co-Ni molar ratio shows the best photocatalytic activity. • • O 2 - and • OH are the main ROS in the photocatalytic degradation of aqueous pollutants. • A direct Z-scheme charge transfer mechanism over CoNiWO 4 /g-C 3 N 4 is proposed.

PREPARATION AND PHOTOCATALYTIC ACTIVITY OF NOVEL PPy/GO/BiVO4 NANOCOMPOSITES

A new type of poly pyrrole/graphene oxide/bismuth vanadate (PPy/GO/BiVO4) ternary nanocomposite with excellent visible light-driven photocatalytic degradation performance was prepared by the traditional hydrothermal method. The photocatalyst samples were characterized and analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). Under visible light irradiation, the photocatalytic activity of the samples in the degradation of Rhodamine B (RhB), which was used to simulate organic dye pollutants in the real natural environment, was detected. The experimental results demonstrated that the photocatalytic degradation performance of PPy/GO/BiVO4 was reinforced after loading GO and PPy. Among all the photocatalyst samples with different PPy content, the PPy/GO/BiVO4 nanocomposite containing 5% PPy showed the highest photocatalytic activity. The stability test suggested that the nanocomposite remained stable even after four cycles of photocatalytic degradation of RhB. As a novel type of visible light-driven photocatalyst, PPy/GO/BiVO4 can be utilized to degrade pollutants in waste water.

Study on the adsorption-photocatalysis properties of g-C3N4/diatomite in the treatment of colour organic compound Rhodamine B

This paper reports the results of the study on the adsorption - photocatalytic degradation of Rhodamine B (RhB) on graphitic carbon nitride g-C3N4 and g-C3N4dispersed on diatomite with 5, 10, 15, and 20% loading (%wt). The bare g-C3N4 exhibits good photocatalytic activity for RhB degradation but weak RhB adsorption. The apparent kinetics of RhB photocatalytic degradation is of order 1/2 regard to RhB. Increasing adsorption - catalysis effect is observed as g-C3N4 is dispersed on diatomite. This potential bifunctional material is capable of both adsorbing and catalysing RhB treatment. The optimum g-C3N4 content on diatomite is 15%.

Synthesis of g-C3N4-C60 fullerene nanowhisker composites and its photocatalytic activity for degradation of rhodamine B

Graphitic carbon nitride (g-C3N4) was prepared from melamine (C3H6N6) by annealing it under an electric furnace at 550 °C for 3 h. The g-C3N4 solution was prepared by dissolving powdered g-C3N4 in an aqueous solution with polyvinyl pyrrolidone (PVP). The liquid–liquid interfacial precipitation (LLIP) method was used to prepare the g-C3N4–C60 fullerene nanowhisker composites from g-C3N4 solution, C60-saturated toluene, and isopropyl alcohol (IPA). X-ray diffraction, scanning electron microscopy, Raman spectroscopy, and transmission electron microscopy were used to characterize the g-C3N4–C60 fullerene nanowhisker composites. These were further used for the photocatalytic degradation of rhodamine B (RhB) under ultraviolet (at 254 and 365 nm) irradiation. In addition, UV–vis spectroscopy was utilized to confirm the photocatalytic degradation activity of RhB over the g-C3N4–C60 fullerene nanowhisker composites. Under UV irradiation, the kinetics of photocatalytic degradation of RhB using g-C3N4–C60 fullerene nanowhisker composites followed a pseudo first-order reaction rate law.

Visible light-driven photocatalyst: An iron(III) coordination compound in Rhodamine B degradation

Rhodamine B (RhB) was photocatalytically degraded by an iron(III) complex (FeL3, L = Methyl 3-hydroxy-2-propenedithioate). The photocatalysts were synthesized, supported on glass slides, and characterized by elemental analyses, IR, UV–vis, Raman, TGA, XPS, Diffuse Reflectance spectroscopy, and Powder X-ray diffraction analyses. The iron complex was also impregnated onto titania (TiO2) films to enhance the photocatalytic performance of this oxide. The structure of the complex does not change when supported on a glass substrate. The FeL3 showed a band gap value (Eg = 1.32 eV) lower than TiO2 (Eg = 3.38 eV), whereas the FeL3 sensitized titania showed the highest Eg value (Eg = 3.41 eV). The photocatalytic degradation of RhB by the TiO2-FeL3 system (27%) after 180 min of reaction slightly improves the performance of TiO2 (22%). Remarkably, FeL3 film showed the best performance (34%). When using scavengers, the degradation reveals that the produced superoxide radicals seem to be responsible for the RhB degradation.

WO3/Ag2CO3 Mixed Photocatalyst with Enhanced Photocatalytic Activity for Organic Dye Degradation.

The development of an efficient photocatalyst with superior activity under visible light has been regarded as a significant strategy for pollutant degradation and environmental remediation. Herein, a series of WO3/Ag2CO3 mixed photocatalysts with different proportions were prepared by a simple mixing method and characterized by XRD, SEM, TEM, XPS, and DRS techniques. The photocatalytic performance of the WO3/Ag2CO3 mixed photocatalyst was investigated by the degradation of rhodamine B (RhB) under visible light irradiation (λ > 400 nm). The photocatalytic efficiency of the mixed WO3/Ag2CO3 photocatalyst was rapidly increased with the proportion of Ag2CO3 up to 5%. The degradation percentage of RhB by WO3/Ag2CO3–5% reached 99.7% within 8 min. The pseudo-first-order reaction rate constant of WO3/Ag2CO3–5% (0.9591 min–1) was 118- and 14-fold higher than those of WO3 (0.0081 min–1) and Ag2CO3 (0.0663 min–1). The catalytic activities of the mixed photocatalysts are not only higher than those of the WO3 and Ag2CO3 but also higher than that of the WO3/Ag2CO3 composite prepared by the precipitation method. The activity enhancement may be because of the easier separation of photogenerated electron–hole pairs. The photocatalytic mechanism was investigated by free radical capture performance and fluorescence measurement. It was found that light-induced holes (h+) was the major active species and superoxide radicals (·O2–) also played a certain role in photocatalytic degradation of RhB.