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The component for photocatalyst is a developing field in energy production. Various photocatalysts can be synthesized using a variety of techniques. Numerous researchers have identified a wide range of photocatalysts. While ternary-based composite photocatalysts have received relatively little attention, plenty of reviews are available on photocatalysts. We provide a short summary of the most recent and a variety of ternary-based composite photocatalysts here. We discuss gold (Au)-based, silver (Ag) based, zinc oxide (ZnO) based, and other ternary-based composites in this paper. This quick summary will help future demonstrations of increased deterioration efficiency. This will provide insight for future research on ternary-based composite photocatalysts.

This study describes the influence of thermal/plasma treatments on the structure and photocatalytic performance of the Au-doped TiO₂ catalyst. Au (gold) nanoparticles were attached on TiO₂ (Titania) nanoparticle surfaces by conventional deposition precipitation technique and the resulting catalysts were subsequently modified with thermal (at 450°C under vacuum) and plasma (at an ambient temperature under Argon atmosphere for 20 min) treatments. Structural characterization of the modified catalysts was performed by diverse analytical techniques and the photocatalytic activity was evaluated by assessing the degradation of the methylene blue (MB) in water under UV (ultra-violet) irradiations. Results showed that the thermal/plasma treatment significantly influenced the structural features of Au-doped TiO₂ catalyst by altering the morphology, increasing the Au nanoparticles population, improving the Au/TiO₂ catalytic activity, changing the textural properties and reducing the band gap energies thus tuned Au-doped TiO₂ catalyst to higher efficiency. Thermal/plasma treated Au-doped TiO₂ was found to exhibit higher photocatalytic activity than the as-synthesized (pristine sample). This improvement in photocatalytic activity might be due to the cathodic influence of gold in suppressing the electron–hole recombination during the reaction.

In this study, zinc sulfide (ZnS)/titanium oxide(TiO₂) nanoparticles were prepared by a two-step facile hydrothermal method and then annealing at $400^{\circ }\mathrm{\text{C}}$ for 30 min. Also, the transient absorption measurement and photocatalytic activity of ZnS/TiO₂ before and after annealing were investigated. The characterization technique such as the scanning electron microscopy (SEM) and X-ray diffraction (XRD) and UV–Visible spectroscopy have been employed to study the surface morphology and structural details. The SEM image shows the change in the surface morphology due to annealing. The change of the crystal structure of ZnS–TiO₂ is revealed by XRD spectra. The femtosecond transient absorption measurement showed moderate decay over several hundred picoseconds for annealed ZnS/TiO₂. Moreover, improved photocatalytic activity of annealed ZnS/TiO₂ nanoparticles in visible light has been observed.

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.

In this paper, we have successfully synthesized ZnO nanoparticles (Nps) via solution combustion method using sugarcane juice as the novel fuel. The structure and morphology of the synthesized ZnO Nps have been analyzed using various analytical tools. The synthesized ZnO Nps exhibit excellent photocatalytic activity for the degradation of methylene blue dye, indicating that the ZnO Nps are potential photocatalytic semiconductor materials. The synthesized ZnO Nps also show good electrochemical sensing of dopamine. ZnO Nps exhibit significant bactericidal activity against Klebsiella aerogenes, Pseudomonas aeruginosa, Eschesichia coli and Staphylococcus aureus using agar well diffusion method. Furthermore, the ZnO Nps show good antioxidant activity by potentially scavenging 1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The above studies clearly demonstrate versatile applications of ZnO synthesized by simple eco-friendly route.

In this paper, Fe₃O₄@SiO₂@CeO₂@Au core/shell microspheres were synthesized through hydrolysis and solvothermal processes. The results indicated that the magnetic Fe₃O₄ cores were well wrapped by the coating layer of SiO₂/CeO₂ with a thickness of 50 nm, and Au nanoparticles with 35 nm in diameter were attached on the shell. The microspheres showed a monodispersity and superparamagnetism. The composites showed excellent ability to absorb a wide range of wavelengths including visible and NIR region (from 250 nm to 800 nm), making it a potential full solar spectrum response photocatalyst for sunlight applications.

Hierarchical TiO₂/carbon nanocomposites were synthesized by oxidation of two-dimensional (2D) Ti₃C₂ nanosheets at different temperatures. Crystal structures and morphologies of the obtained samples were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and Raman spectroscopy. The results show that 2D Ti₃C₂ nanosheets are partially oxidized to form a novel hierarchical nanostructure which is composed of carbon nanosheets and TiO₂ nanoparticles. With the calcination temperature increasing, the crystal structure of TiO₂ nanoparticles changes from anatase to rutile and the hierarchical structure was gradually destroyed. The photodegradation results reveal that the samples obtained at 200°C and 285°C show much better photocatalytic properties than P25. And meanwhile the photocatalytic property will become worse with the increase in calcinations temperature.

Metal-free photocatalysts trithiocyanuric acid (C₃N₃S${}_3)$ and its polymers were one-step synthesized and used for selective aerobic oxidation of benzyl alcohol under visible light. The S–S bridged C₃N₃S₃ polymers showed higher oxidation activity with increasing polymerization time and reached a maximum at 40h. As a major factor, catalysts’ solubility in water at different temperatures (from 298.15K to 368.15K) was measured at atmospheric pressure. The obtained data were correlated by polynomial empirical equation and modified Apelblat equation, respectively. Experimental results proved that the solubility of C₃N₃S₃ and its polymers increased with increasing temperature. The solubility of C₃N₃S₃ polymers with lower polymerization degree (DP) were better than that of parent C₃N₃S₃ owing to the hydrophilicity caused by a low symmetry and disorder structure, whereas the higher DP could lead to the decrease of polymer solubility and further affect the photocatalytic activity. Thermodynamic properties of the solution system including the enthalpy ($\mathrm{\Delta }{H}_S^0)$ and heat capacity ($c_p^0$) were calculated by the modified Apelblat equation.

Graphene decorated with hierarchical CuS nanoplates (CuS NP-G) was synthesized using a microwave method to be used as a photocatalytic material. The incorporation of graphene into hierarchical CuS nanoplates was confirmed by structural, morphological and optical characterizations. The photocatalytic performance of the nanocomposite was evaluated. This study confirmed that the introduction of graphene was an effective way not only to improve the structural stability and service durability of the composite, but also to improve its solar photocatalytic activity by promoting the electron transfer and charge separation of hierarchical CuS nanoplates.

Development of efficient visible light driven photocatalysts for water splitting has attracted great research interest. Herein, a novel H₂-producing nitrogen-doped graphene quantum dots (NGQDs)-Cu₂O was successfully constructed and synthesized. The as-prepared NGQDs-Cu₂O photocatalysts were benefited for light harvesting and charge separation and showed highly efficient photocatalytic property for hydrogen production by water splitting. Results displayed that the amount of NGQDs exhibited significant influence for H₂ production, and the optimum sample of 3%NGQDs-Cu₂O performed the highest hydrogen-evolution rate of 22.6$\mu$mol h${}^{-1}$ g${}^{-1}$, which was about 2 times higher than that of the pure Cu₂O (10.1$\mu$mol h${}^{-1}$ g${}^{-1}$). By further study, the enhanced photocatalytic performance could be ascribed to the crucial role of NGQDs, which widely improve the separation of photogenerated electron-hole pair’s.

Here, the lamellar-shaped Bi₂S₃ grown on a porous TiO₂ monolith was obtained by a two-step method including a sol–gel route and hydrothermal treatment. The photocatalytic activity of the as-synthesized Bi₂S₃/TiO₂ composites was evaluated for photodegradation of methylene blue (MB) dye in aqueous solution under the visible-light irradiation. Based on our experimental results, 5% (molar ratio of Bi₂S₃ to TiO${}_2)$ Bi₂S₃/TiO₂ photocatalysts exhibited a maximum photodegradation rate of MB up to 96.9% under visible-light irradiation for 120 min. Our findings indicated that the lamellar-shaped Bi₂S₃ can extend the light absorption up to visible areas, and porous TiO₂ can provide enhanced specific surface area and more mass transfer pathway to enhance the photodegradation efficiency. Furthermore, porous TiO₂ can accept the electrons from the Bi₂S₃ conduction band due to the relatively positive electrode potential to impede the photoproduced electron and hole combination to result in advanced photocatalytic performance.

The presence of the antibiotics in the wastewater has posed a huge risk to aquatic life and human health. It is a great significance to develop an effective technology to treat the antibiotics-containing wastewater. In this study, a series of g-C₃N₄/NH₂-MIL-88B(Fe) composite photocatalysts are synthesized through a simple one-step method. The structure and optical properties of prepared photocatalysts are detected by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–Vis absorption spectra (UV–Vis DRS), photoluminescence (PL) spectroscopy and transient photocurrent techniques, respectively. FESEM and TEM show that MOF is uniformly dispersed in petaloid g-C₃N₄. The uniform dispersion of Fe-MOFs in the heterojunction composites increases the specific surface area ($S_{\mathrm{\text{BET}}})$ of g-C₃N₄, which results in a great adsorption property for the nanocomposite. The capture experiment shows that $•$${\text{O}}_2^{-}$ and ${\text{h}}^{+}$ are the main active substances in ciprofloxacin (CIP) degradation. These prepared composite photocatalysts exhibit excellent CIP photodegradation activity under visibly light irradiation with an apparent rate constant of 0.0127${\text{min}}^{-1}$ (3.74 times as the rate of single component). The remarkable catalytic performance can be ascribed to the fact that the g-C₃N₄/NH₂-MIL-88B(Fe) heterojunction inhibits the recombination of photoinduced electron–hole pairs and improved the visible light absorption.

A new protocol was developed to obtain a composite photocatalyst by incorporating indium to ZnO and subsequently assembling it with reduced graphene oxide (RGO) sheets. The incorporation of indium led to lattice distortion of ZnO and introduction of defect levels. The hybridization with RGO could improve the electron transport and extend the lifetime of photo-generated carriers, leading to enhanced activity for dye degradation driven by visible light. The photocatalytic activity appeared to be dependent on the relative quantity of RGO. The optimized quantity resulted in the highest activity due to the dual role of electron shuttle and "shielding effect" of RGO. In addition, the composite photocatalyst exhibited excellent repeatable use performance, suggestive of its high stability. This study proposed a promising strategy to construct photocatalysts by rational bandgap engineering and tunable composite technology.

We report a simple synthesis of C-doped ZnO composite nanoparticles by a solvothermal treatment of Zn(OAc)₂ ⋅ 2H₂O that provides a source of both zinc and carbon. The photocatalytic activities of the composites were evaluated by the degree of degradation rhodamine B in aqueous solutions at room temperature with near UV light irradiation. These nanocomposites exhibit higher photocatalytic activity compared with pure ZnO nanoparticles. The enhancement of photocatalytic activity of C-doped ZnO nanoparticles is mainly attributed to their absorbed more photons and reduced electron hole pair recombination.

La-modified ZnO nanosheet-assembled flower-like microstructures, were successfully obtained through a facile two-step solution-based strategy including a simple aqueous solution and subsequent impregnation technique. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and ultraviolet-visible spectrometer (UV-Vis) were employed to characterize the morphology, composition, crystal structure and photocatalytic properties of prepared products in detail. The photocatalysis test results revealed that the La-modified ZnO nanoflowers displayed greatly enhanced catalytic performance and the decomposition efficiency was up to about 99.60%, which was mainly ascribed to the increased charge separation rate on the La-modified surface of ZnO nanosheets and the high surface area of the flower-like structure.

Well-defined flowerlike Bi₂O₂CO₃ nanostructures were fabricated by a simple one-pot solvothermal method with high yield. The products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy, transmission electron microscopy, nitrogen sorption, photoluminescence spectra and UV–visible diffuse reflectance spectroscopy. The photocatalytic properties of the as-prepared samples were further investigated by photocatalytic decomposition of Rhodamine B (RhB) dye, and it was found that the Bi₂O₂CO₃ nanoflowers showed a good photocatalytic activity under UV light. The excellent photocatalytic performance of Bi₂O₂CO₃ flowerlike nanostructures is related to its special nanostructure and morphology, indicates its potential application in photocatalysis and nanosensors.

We report a facile easy method to deposit anatase titania (TiO${}_2)$ on cellulose paper. The anatase TiO₂/cellulose paper (ATCP) was characterized by scanning electron microscopy, transmission electron microscope, energy dispersive X-ray spectrometer, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. This hybrid paper with the anatase TiO₂ content of around 13.86wt.% can serve as an eco-friendly flexible photocatalyst, which can rapidly degrade blue indigo carmine dye into a colorless solution within 30min under UV radiation. Moreover, compared to commercially available TiO₂ P25 and anatase TiO₂ powder, a faster decomposition rate of indigo carmine dye was acquired when using ATCP. These results suggest that this hybrid paper might be useful in the treatment of organic dye wastewater.

The bismuth vanadate (BiVO₄) photocatalyst was successfully synthesized by an organic-aqueous hetero-phase reaction method using organic additives (oleic acid, oleyl alcohol, and oleylamine) to investigate the reaction mechanism. The BiVO₄ with a star-like morphology could be synthesized with oleylamine. Bismuth precursors formed by the interaction between bismuth and the amino group of oleylamine were nano-sized complex particles with amorphous phase, finally resulted in the formation of star-like morphology. Moreover, BiVO₄ synthesized with oleylamine showed excellent photocatalytic activity on degradation of rhodamine B.

Herein, Al₂(WO${}_4{)}_3$/Bi₂WO₆ heterojunctions with $Z$-type structure were successfully prepared by a one-step hydrothermal method. Moreover, the effects of different composite ratios on the properties of materials were explored. The electrochemical tests and photocatalytic degradation experiments showed that the corresponding Al₂(WO${}_4{)}_3$/Bi₂WO₆ heterojunctions all exhibited improved electrochemical performance and photocatalytic performance than that of the bare Bi₂WO₆ material. Especially, when the molar ratio of Al to Bi was 2:1, the obtained Al₂(WO${}_4{)}_3$/Bi₂WO₆ heterojunction displayed the optimal photoelectric and photocatalytic performance. In detail, it depicted the highest photocurrent density, the smallest resistance and the fastest charge transfer rate. What’s more, the RhB solution (10 ppm) could be completely degraded in 30 min under visible-light irradiation, and the removal rate was almost 1.6 times than that of pure Bi₂WO₆ nanosheets. In the same condition, it also exhibited excellent photocatalytic performance for the degradation of tetracycline (TC) solution (10 ppm) and the K₂Cr₂O₇ solution (40 ppm). These results fully manifested that the constructed Al₂(WO${}_4{)}_3$/Bi₂WO₆ heterojunction possessed superior photoelectric conversion capacity and outstanding photocatalytic performance. Moreover, based on the obtained experimental results, a $Z$-scheme mechanism of catalytic degradation of RhB and TC under simulated solar light was proposed and discussed.

The effective utilisation of solar radiation requires the development of novel photocatalysts activated by visible-light. Activity tests of toluene decomposition were carried out in the presence of modified titanium dioxide photocatalysts in which some oxygen ions were substituted by sulfur. The elimination of toluene after 1 hour irradiation of the photocatalysts by a pulsed blue LED yielded 44 percent elimination. Pretreatment in which S-doped TiO₂ was irradiated by UV for 1 hour prior to the activity test was effective in decomposing acetaldehyde, even under a pulsed green LED irradiation.