Facile Photodeposition Research Articles

Dipole field as charge-transfer bridge between Cu atomic clusters/PtCu alloy nanocubes and nitrogen-rich C3N5 for superior photocatalytic hydrogen evolution

Utilizing spontaneous polarization field to harness charge transfer kinetics is a promising strategy to boost photocatalytic performance. Herein, a novel Cu atom clusters/PtCu alloy nanocubes coloaded on nitrogen-rich triazole-based C3N5 (PtCu-C3N5) with dipole field was constructed through facile photo-deposition and impregnation method. The dipole field-drive spontaneous polarization in C3N5 acts as a charge-transfer bridge to promote directional electron migration from C3N5 to Cu atom clusters/PtCu alloy. Through the synergistic effects between Cu atom clusters, PtCu alloy and dipole field in C3N5, the optimized Pt2Cu3-C3N5 achieved a record-high performance with H2 formation rate of 4090.4 μmol g−1 h−1 under visible light, about 154.4-fold increase compared with pristine C3N5 (26.5 μmol g−1 h−1). Moreover, the apparent quantum efficiency was up to 25.33 % at 320 nm, which is greatly superior than most previous related-works. The directional charge transfer mechanism was analyzed in detail through various characterizations and DFT calculations. This work offers a novel pathway to construct high-efficiency multi-metal photocatalysts for solar energy conversion.

Oxidative and selective C–C cleavage of glycerol to glycolaldehyde with atom-like Cu on Cu-TiO2: Photocatalytic water reduction with concurrent glycerol oxidation in sunlight

Concurrent consumption of electrons and holes for the conversion of a biomass component to value added products represents a highly efficient and sustainable approach towards utilizing renewable energy, but difficult to achieve. The integration of hydrogen production with glycerol oxidation presents a novel and sustainable approach towards achieving a circular economy. In the current study, integration of atom-like Cu-clusters onto TiO2 substrate has been achieved using a facile photo-deposition technique (TC-PDO). Also, novel synthetic approaches have been employed to augment the surface coverage of Cu on TiO2 with atom-like clusters of Cu, either by borohydride treatment on TiO2 followed by Cu-deposition (TC-200) or oxygen-vacancy creation by UV illumination followed by Cu-deposition (TC-PDO). Increased dispersion and enhanced electronic integration of Cu with TiO2 lead to a corresponding increase in the efficiency of photocatalytic hydrogen evolution (13.8 mmol/h.g for TC-PDO at pH 9). Several atom-like Cu integrated with each TiO2 particle acts as photocatalytic reactor, and the same enhances electron-hole separation as well as activity. Sustainable aspect was also studied for TC-PDO up to 25 h at pH 9. Concurrently, glycerol oxidation displays the highest selectivity to C2 product (glycolaldehyde with 70 %) with a C–C cleavage. The investigation of this process holds significant potential for the extensive and simultaneous exploitation of electrons and holes in order to achieve water splitting and glycerol oxidation towards selective value-added products formation.

Comparative study of photocatalytic H2 production by nickel chalcogenides1+x based Zn3In2S6 photocatalytic system

Exploiting metal chalcogenide-based photocatalysts has fascinated researchers as a source of green hydrogen (H2) energy. Herein, we have designed a novel selenium-enriched NiSe1+x/ZIS (NiSexZ) photocatalytic system via a two-step hydrothermal and facile photo-deposition method. It was fascinating to conclude here that the NiSexZ photocatalytic system showed boosted H2 evolution results in comparison with other sulphur-enriched NiS1+x/ZIS (NiSxZ) and tellurium-enriched NiTe1+x/ZIS (NiTexZ). The optimized NiSe0.5Z composite exhibited a photocatalytic H2 evolution of 3.24 mmol g-1 h-1, a 9.8-fold increase over pure ZIS and it demonstrated an apparent quantum efficiency (AQE) of 2.06 % via 420 nm filter. Moreover, sulphur (S), selenium (Se), and tellurium (Te) synergistic active sites were exposed to promote H2 evolution reaction in this work. Given the significant advancements and commendable performance exhibited by the Se-Hads across the week bond, it is extremely probable that the NiSe1+x cocatalyst holds immense potential for the development of sophisticated photocatalytic materials.

Dual built-in spontaneous electric fields in an S-scheme heterojunction for enhanced photocatalytic H2O2 production

A facile photodeposition method was used to selectively modify Cu2O and MnOOH on BiVO4. The improved H2O2-production activity was mainly attributed to the dual built-in electric field in the BiVO4/Cu2O S-scheme heterojunction.

Visible-light-driven Au/PCN-224/Cu(II) modified fabric with enhanced photocatalytic antibacterial and degradation activity and mechanism insight

The development of novel photocatalytic platform for efficient water purification and sterilization is of utmost importance due to the significant threat of chronic diseases resulting from water pollution and bacterial contamination. Herein, a high-efficiency, easy-recyclable, and environment-friendly photocatalytic fabric was developed as a water disinfection and organic pollutant degradation platform. In which, microamounts of Au nanoparticles (2 wt%) and Cu(II) clusters (2.5 wt%) co-decorated porphyrinic MOF (Au/PCN-224/Cu(II)) coating was applied as photocatalytic surface, and flexible cotton fabric served as stable support. Au/PCN-224/Cu(II) composite photocatalyst was prepared via a facile photo-deposition procedure followed by impregnation method, and further immobilized onto polydopamine (PDA) pre-treated cotton fabric through catechol-amine reaction. The fabricated photocatalytic platform exhibited excellent ability to generate reactive oxygen species (ROS) by multiple routes under low-power visible light irradiation, and achieved efficient photodisinfection effects for causative organism including Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) without the obvious leakage of metal ions from the potocatalyst during the reaction. Additionally, the reaction rate constant for organic dye MB photodegradation achieved by Au/PCN-224/Cu(II)@Fabric was 3.73 times higher than that of PCN-224@Fabric, and the degradation intermediates analysis was also conducted. The band alignments of PCN-224, Au/PCN-224, Au/PCN-224/Cu(II) photocatalysts were determined, and the charge transfer mechanism within Au/PCN-224/Cu(II) photocatalyst was elucidated through the utilization of DRS, Mott − Schottky, ESR, EIS, and photocurrent analyses. It is suggested that the deposition of Au and doping of Cu(II) both with small amounts enhanced the light absorption capacity, and also improved the charge separation ability through the surface plasmon resonance (SPR) effect and interfacial electron transfer (IFCT) mechanism. Moreover, Au SPR and Cu doping exhibited a substantial enhancement in photothermal conversion effect, thereby synergistically reinforcing the sterilization performance. This work provides an approach for the development of effective photocatalytic platform based on porphyrinic MOFs combined with trace metal co-catalysts in the application of water disinfection and purification.

Visible light-supported efficient photocatalytic disinfection using a robust silver-doped boron photocatalyst

Photocatalytic sterilization is attracting attention because of its potential to prevent the dissemination of antimicrobial resistance.Here, a novel silver-doped boron (AgB) photocatalyst was synthesized through a facile photodeposition approach, which was comprehensively characterized and implemented in photocatalytic disinfection of antibiotic-resistant bacteria (ARB). Compared with boron without doping, AgB demonstrated superior photocatalytic disinfection activity (5.57-log reduction in 60 min) towards Escherichia coil K-12 under solar light irradiation. More importantly, no ARB regrowth after 48 h was observed after the treatment by AgB-assisted photocatalysis. This efficient and stable disinfection was achieved because the doped Ag serves as an electron mediator, facilitating rapid electron transfer and effective separation efficiency of electron-hole pairs. Moreover, the tight bonding between Ag and boron reduces the dissolution of silver ions and improves the catalytic stability. These two features jointly benefit the production of reactive species, and the trapping experiments suggested that holes (h+) and superoxide radicals (•O2−) played dominant roles in bacterial inactivation.

Tuning charge transfer between size-controlled Pt cluster and N vacancy engineered ultrathin g-C3N4 for efficient photocatalytic hydrogen evolution

Rational design and development of metal-cluster co-catalysts with regulated charge transfer interface is an effective strategy to fabricate highly active photocatalysis. Here, Pt clusters are elaborately incorporated onto N vacancy engineered ultrathin g-C3N4 (vUCN) by a facile photo-deposition method. The targeted vUCN-300Pt with cluster size of 1.1 nm and dispersion density of 104 μg m−2 exhibits an optimal photocatalytic rate of 862.4 μmol h−1 g−1, which is approximate 40 times and 5.3 times higher than that of pristine g-C3N4 and vUCN. The inherent reason for the superior property lies on the efficient electron transfer pathway, in which electrons are effectively migrated to the surface assisted by the ultrathin structure and appropriate N vacancies, and subsequently directed towards the neighboring Pt cluster. Additionally, the light absorption ability and the proton reduction kinetics are both promoted under the collaborative optimization of the band-gap structure by Pt cluster and vUCN. Afterwards the Pt site with reduced Gibbs free energy could serve as a highly active medium for combining H* and the transferred electron to achieve efficient H2 evolution. The relevance of these findings provides useful guideline for tuning the reactive metal-support interaction (RMSI) between Pt cluster and g-C3N4-based catalysts.

Position-selected cocatalyst modification on a Z-scheme Cd0.5Zn0.5S/NiTiO3 photocatalyst for boosted H2 evolution

Photocatalytic water splitting by semiconductors is a promising technology to produce clean H2 fuel, but the efficiency is restrained seriously by the high overpotential of the H2-evolution reaction together with the high recombination rate of photoinduced charges. To enhance H2 production, it is highly desirable yet challenging to explore an efficient reductive cocatalyst and place it precisely on the right sites of the photocatalyst surface to work the proton reduction reaction exclusively. Herein, the metalloid NixP cocatalyst is exactly positioned on the Z-scheme Cd0.5Zn0.5S/NiTiO3 (CZS/NTO) heterostructure through a facile photodeposition strategy, which renders the cocatalyst form solely at the electron-collecting locations. It is revealed that the directional transfer of photoexcited electrons from Cd0.5Zn0.5S to NixP suppresses the quenching of charge carriers. Under visible light, the CZS/NTO hybrid loaded with the NixP cocatalyst exhibits an optimal H2 yield rate of 1103 μmol h−1 (i.e., 27.57 mmol h−1 g−1), which is about twofold of pristine CZS/NTO and comparable to the counterpart deposited with the Pt cocatalyst. Besides, the high apparent quantum yield (AQY) of 56% is reached at 400 nm. Further, the mechanisms of the cocatalyst formation and the H2 generation reaction are discussed in detail.

Which Is More Efficient in Promoting the Photocatalytic H2 Evolution Performance of g-C3N4: Monometallic Nanocrystal, Heterostructural Nanocrystal, or Bimetallic Nanocrystal?

Generally, an excellent cocatalyst could promote the photocatalytic hydrogen (H2) evolution performance of g-C3N4 significantly. Herein, a superior cocatalyst of gold-platinum (AuPt) nanocrystal with an ultralow content of Pt was successfully decorated on carbon self-doping g-C3N4 nanosheets (AuPt/CCN) via a facile photodeposition route. The corresponding Pt/CCN, Au/CCN, Au/Pt/CCN, and Pt/Au/CCN were also prepared for comparison. It is found that AuPt/CCN exhibits much superior photocatalytic H2 evolution performance (1135 μmol/h) when irradiated with a 300 W Xe lamp, up to 20, 12, 5, 2, and 1.5 times that of the pristine CCN, Pt/CCN, Au/CCN, Au/Pt/CCN, and Pt/Au/CCN, respectively. The quantum efficiency (QE) of AuPt/CCN at 420 nm reaches 12.5%. The experimental and density functional theory calculation results suggested that the improved AuPt performance can be mainly ascribed to the non-plasmon-related synergistic effect of Au and Pt atoms in AuPt nanocrystal: (1) the proximity and the electronegativity difference of Au and Pt atoms in AuPt accelerate the transfer and separation of charge carriers and (2) the synergistic interaction between Pt and Au atoms optimizes the Gibbs free energy (ΔGH*) of H* (atom) adsorption on AuPt, promoting the H2 generation kinetics of AuPt/CCN.

Brookite TiO2 Nanoparticles Decorated with Ag/MnOx Dual Cocatalysts for Remarkably Boosted Photocatalytic Performance of the CO2 Reduction Reaction.

The solar-driven CO2 reduction reaction (CO2RR) for producing chemical fuels is considered to be a promising approach to dealing with the growing energy crisis and greenhouse effect. Herein, novel Ag/MnOx dual-cocatalyst-decorated brookite titania (BT) nanoparticles with remarkably boosted photocatalytic CO2RR performance are prepared through a facile photodeposition method. The resultant xAg-BT-yMn composite with optimal cocatalyst content delivers amazing CO/CH4 yields of 31.70/129.98 μmol g-1 with an overall photoactivity of 1103.28 μmol g-1 h-1, 11.98 times higher than that of the BT nanoparticles alone. Further investigations demonstrate that the dual cocatalysts decorating the BT nanoparticles not only effectively retard the photoinduced charge recombination but also significantly vary the surface chemical feature to promote the adsorption/activation of the reactants (CO2/H2O). In addition, the Ag nanoparticles can broaden the spectral response region, while the MnOx cocatalyst can promote the CH4 product selectivity and the water oxidation reaction. The synergistic effect of Ag/MnOx dual cocatalysts on the BT nanoparticles renders a remarkably boosted CO2RR performance, which provides a simple yet general synthesis strategy for brookite titania-based photocatalysts with high-performance solar-driven CO2 conversion.

Synergistic Effect of Cu Single Atoms and Au-Cu Alloy Nanoparticles on TiO2 for Efficient CO2 Photoreduction.

The synergy between metal alloy nanoparticles (NPs) and single atoms (SAs) should maximize the catalytic activity. However, there are no relevant reports on photocatalytic CO2 reduction via utilizing the synergy between SAs and alloy NPs. Herein, we developed a facile photodeposition method to coload the Cu SAs and Au-Cu alloy NPs on TiO2 for the photocatalytic synthesis of solar fuels with CO2 and H2O. The optimized photocatalyst achieved record-high performance with formation rates of 3578.9 for CH4 and 369.8 μmol g-1 h-1 for C2H4, making it significantly more realistic to implement sunlight-driven synthesis of value-added solar fuels. The combined in situ FT-IR spectra and DFT calculations revealed the molecular mechanisms of photocatalytic CO2 reduction and C-C coupling to form C2H4. We proposed that the synergistic function of Cu SAs and Au-Cu alloy NPs could enhance the adsorption activation of CO2 and H2O and lower the overall activation energy barrier (including the rate-determining step) for the CH4 and C2H4 formation. These factors all enable highly efficient and stable production of solar fuels of CH4 and C2H4. The concept of synergistic SAs and metal alloys cocatalysts can be extended to other systems, thus contributing to the development of more effective cocatalysts.

Au@GO@g-C3N4 and Fe2O3 nanocomposite for efficient photocatalytic and electrochemical applications

Graphene oxide (GO), graphitic carbon nitride (g-C3N4), iron oxide (Fe2O3), and gold nanoparticle-based nanocomposite (Au/GOCNIONPs) has been synthesized using four different routes in order to study several applications. The GO, Fe2O3, and g-C3N4 samples were prepared via Modified hummer, co-precipitation, and thermal exfoliation method, respectively. The facile photo deposition method was adopted for anchoring Au NPs onto g-C3N4 to get the finely structured nanocomposite. Au/GOCNIONPs nanocomposite revealed a face-centered hexagonal structure with an average particle size of 10.67 nm. The XRD peaks of the synthesized nanocomposite were confirmed using JCPDS data card # (00-013-0458), (04-0784), and (87-1526). The Au/GOCNIONPs nanocomposite showed 93.9% and 90.1 % degradation efficiency against the methylene blue (MB) and Rhodamine B dyes. The synergetic effect of the iron oxide nanoparticles decorated graphene oxide graphitic carbon nitride nanocomposite has shown substantially enhanced and fast dyes degradation within no time that makes it unique compared with other nanocomposites. Moreover, better Photo Luminescence results at the lower excitation wavelength, antibacterial activity results, good stability at comparatively high temperature, super specific-capacitance are the main findings confirming the superior performance of the prepared nanocomposite as compared with other composites, has been a tempting nominee regarding its feasibility, efficiency, and versatility to be used in future.

CdS quantum dots-decorated InOOH: Facile synthesis and excellent photocatalytic activity under visible light

For the first time, CdS quantum dots (QDs)-decorated InOOH (CdS-In for short) was synthesized by a facile photodeposition method. The experiment results showed that CdS-In samples exhibited excellent activity and stability towards photocatalytic reduction of nitro aromatics. The conversion ratio of 4-nitroaniline (4-NA) over CdS-In sample that was prepared with photodeposition time of 120 min (CdS-In-120) reached up to 99.4% under visible light irradiation for 40 min, which was even higher than that achieved over commercial CdS (86.2%). Besides the significant enhancement of visible light absorption, quantum sized CdS were decorated evenly on the surface of InOOH, which was very beneficial for the high activity. Furthermore, the heterogeneous junction formed at the interface of CdS QDs and InOOH can significantly increase the separation efficiency of photogenerated charge carriers. Active species control experiment and electron spin resonance (ESR) technique have proved that photogenerated electrons are the main active species towards photocatalytic reduction of nitro aromatics. It is anticipated that our study would offer meaningful insights for exploring novel InOOH-based visible light photocatalysts towards efficient reduction of nitro aromatics.

Highly efficient BiVO4 single-crystal nanosheets with dual modification: phosphorus doping and selective Ag modification

BiVO4, a visible-light response photocatalyst, has shown tremendous potential because of abundant raw material sources, good stability and low cost. There exist some limitations for further applicaitions due to poor capability to separate electron–hole pairs. In fact, a single-component modification strategy is barely adequate to obtain highly efficient photocatalytic performance. In this work, P substituted some of the V atoms from VO4 oxoanions, namely P was doped into the V sites in the host lattice of BiVO4 by a hydrothermal route. Meanwhile, Ag as an attractive and efficient electron-cocatalyst was selectively modified on the (010) facet of BiVO4 nanosheets via facile photo-deposition. As a result, the obtained dually modified BiVO4 sheets exhibited enhanced photocatalytic degradation property of methylene blue (MB). In detail, photocatalytic rate constant (k) was 2.285 min−1 g−1, which was 2.78 times higher than pristine BiVO4 nanosheets. Actually, P-doping favored the formation of O vacancies, led to more charge carriers, and facilitated photocatalytic reaction. On the other hand, metallic Ag loaded on (010) facet effectively transferred photogenerated electrons, which consequently helped electron–hole pairs separation. The present work may enlighten new thoughts for smart design and controllable synthesis of highly efficient photocatalytic materials.

Gallium phosphide photoanodes coated with nickel oxyhydroxide cocatalyst for stable photoelectrochemical water splitting reactions

Gallium phosphide (GaP) is a promising material for photoelectrochemical (PEC) water splitting due to its appropriate bandgap and straddling band alignment with the water redox level. However, it suffers from poor charge transport and sluggish reaction kinetics. To mitigate these limitations and improve the PEC water splitting efficiency, simple and facile photodeposition followed by electrodeposition of nickel oxyhydroxide (NiOOH) as a cocatalyst on GaP was carried out. As a result, NiOOH-deposited GaP photoanodes exhibit much-improved PEC water splitting performance compared to bare GaP photoanode. The optimally deposited NiOOH cocatalyst on GaP enhanced the PEC activity of the photoanode with a photocurrent density of 1.15 mA/cm2, giving rise to a 10-fold enhancement compared to bare GaP (0.114 mA/cm2) and shifting the onset potential towards water reduction potentials (−553 mV vs Ag/AgCl). The best photoanode showed a 1.38% photoconversion efficiency at 0 V vs Ag/AgCl, which was 10 times higher than the bare GaP photoanodes (0.142%). Furthermore, all the NiOOH-deposited GaP photoanodes manifested long-term stability over 40000 s under illumination. The enhancement is attributed to the reduced onset potential, enhanced reaction kinetics by efficiently transporting the photogenerated holes and preventing the corrosion of GaP surface upon deposition of NiOOH cocatalyst.

Visible light driven selective photocatalytic synthesis of high-value carbonyl compounds from glycerol over Ag-AgBr/TiO2 nanocomposites in acetonitrile

Ag-AgBr/TiO2 ternary nanocomposites fabricated by facile photo-deposition were applied for selective oxidation of glycerol into glyceraldehyde (GAD) and dihydroxyacetone (DHA) in non-aqueous solvent under aerobic conditions. Although a lower conversion of glycerol was observed in acetonitrile than in water after 240 min, a significantly higher yield of GAD (19%) and DHA (13%) was obtained likely due to the lower generation of non-selective •OH radicals in the non-aqueous solvent. Obtained results underscore the vital role of solvent in photocatalytic upgrading of glycerol.

Photochemical synthesis of Ni-Ni(OH)2 synergistic cocatalysts hybridized with CdS nanorods for efficient photocatalytic hydrogen evolution

Ni-Ni(OH)2 composite was synthesized by a novel and facile photodeposition strategy and used as the cocatalyst of CdS for solar-to-hydrogen conversion. Under visible light, the hydrogen evolution rate of Ni-Ni(OH)2/CdS was 428 mmol g−1h−1 and remained essentially unchanged after 24 h in Na2S/Na2SO3 aqueous solution. In particular, the Ni-Ni(OH)2/CdS also displayed excellent photocatalytic hydrogen evolution reaction (HER) activity (13.3 mmol g−1h−1) in 40 vol% glycerol. A set of spectroscopy and electrochemical characterizations were performed to explore the photoinduced interfacial charge dynamics. Ni and Ni(OH)2 were synergistic cocatalysts for improving charge utilization and photocatalytic performance.

Efficient photocatalytic degradation of dyes using photo-deposited Ag nanoparticles on ZnO structures: simple morphological control of ZnO.

In this work, morphology-controlled ZnO structures were prepared via a hydrothermal method by simple adjustments in the NaOH concentration. The NaOH concentration variation from 0.2 to 1.2 M resulted in the formation of ZnO structures in shapes such as walnut, spherical flower, flower, rod, and urchin-like. The extent of OH− ions is the main factor influencing the growth of ZnO structures. Well-defined morphologies, good crystallinity, and optical properties were obtained for all ZnO structures. Among these ZnO structures, ZnOsf (spherical flower-like) structure showed a greater percentage of photodegradation of methyl orange and rhodamine B dyes. Surface plasmon resonance was achieved by modifying the surface of ZnO with Ag nanoparticles. ZnOsf was loaded with Ag nanoparticles by a facile photo-deposition method. Ag–ZnOsf showed superior photoactivity and recyclability for the degradation of methyl orange and rhodamine B. Therefore, modification of different ZnO structures can help realize potential catalysts for future environmental applications.

The Photocatalytic and Antibacterial Performance of Nitrogen-Doped TiO2: Surface-Structure Dependence and Silver-Deposition Effect.

Catalysts for visible-light-driven oxidative cleaning processes and antibacterial applications (also in the dark) were developed. In order to extend the photoactivity of titanium dioxide into the visible region, nitrogen-doped TiO2 catalysts with hollow and non-hollow structures were synthesized by co-precipitation (NT-A) and sol–gel (NT-U) methods, respectively. To increase their photocatalytic and antibacterial efficiencies, various amounts of silver were successfully loaded on the surfaces of these catalysts by using a facile photo-deposition technique. Their physical and chemical properties were evaluated by using scanning electron microscopy (SEM), transmission electron microscopy–energy dispersive X-ray spectroscopy (TEM–EDS), Brunauer–Emmett–Teller (BET) surface area, X-ray diffraction (XRD), and diffuse reflectance spectra (DRS). The photocatalytic performances of the synthesized catalysts were examined in coumarin and 1,4-hydroquinone solutions. The results showed that the hollow structure of NT-A played an important role in obtaining high specific surface area and appreciable photoactivity. In addition, Ag-loading on the surface of non-hollow structured NT-U could double the photocatalytic performance with an optimum Ag concentration of 10−6 mol g−1, while a slight but monotonous decrease was caused in this respect for the hollow surface of NTA upon increasing Ag concentration. Comparing the catalysts with different structures regarding the photocatalytic performance, silverized non-hollow NT-U proved competitive with the hollow NT-A catalyst without Ag-loading for efficient visible-light-driven photocatalytic oxidative degradations. The former one, due to the silver nanoparticles on the catalyst surface, displayed an appreciable antibacterial activity, which was comparable to that of a reference material practically applied for disinfection in polymer coatings.

Construction of highly efficient Z-scheme ZnxCd1-xS/Au@g-C3N4 ternary heterojunction composite for visible-light-driven photocatalytic reduction of CO2 to solar fuel

Converting CO2 into renewable solar fuel using photocatalysts is one of the most ideal solutions for environmental challenges and energy crises. Here, the solid-solid Z-scheme Zn0.5Cd0.5S/Au@g-C3N4 (ZCS/Au@CN) heterojunction showed improved photocatalytic reduction of CO2 due to the enhanced visible light consumption, fast dissolution of photogenerated electron-hole pairs, quick interfacial transfer process of electrons, and enlarged surface area. Under visible-light irradiation, methanol (CH3OH) was produced at a rate of 1.31 μmol h−1 g−1 over ZCS/Au@CN, roughly 43.6 and 32.7 folds higher than those observed over pure ZCS and CN samples. The analytical characterization results verified the role of AuNPs as an electron mediator, which improved the rapid extraction of photoinduced electrons and enhanced the reduction ability of CO2. This work not only demonstrates a facile photodeposition assisted hydrothermal method for fabrication of ZnxCd1-xS/Au@C3N4 heterojunction composite photocatalysts but also demonstrates the possibility of utilizing ternary composites for enhanced photocatalytic reduction of CO2.