Binary Photocatalysts Research Articles

Tailoring Advanced CdS Anisotropy-Driven Charge Spatial Vectorial Separation and Migration via In Situ Dual Co-Catalyst Synergistic Layout.

Tailoring advanced anisotropy-driven efficient separation and migration of photogenerated carriers is a pivotal stride toward enhancing photocatalytic activity. Here, CdS-MoS2 binary photocatalysts are tailored into a dumbbell shape by leveraging the rod-shaped morphology of CdS and employing an in situ tip-induction strategy. To further enhance the photocatalytic activity, an in situ photo-deposition strategy is incorporated to cultivate MnOx particles on the dumbbell-shaped CdS-MoS2. The in situ deposition of MnOx effectively isolated the oxidatively active sites on the CdS surface, emphasizing the reductively active crystalline face of CdS, specifically the (002) face. Benefiting from its robust activity as a reduction active site, MoS2 adeptly captures photogenerated electrons, facilitating the reduction of H+ to produce hydrogen. The anisotropically driven separation of CdS photogenerated carriers markedly mitigates the Coulomb force or binding force of the photogenerated electrons, thus promoting a smoother migration toward the active site for photocatalytic hydrogen evolution. The hydrogen evolution rate of 35MnOx-CdS-MoS2-3 surpasses that of CdS by nearly an order of magnitude, achieving a quantum efficiency of 22.30% at 450nm. Under simulated solar irradiation, it attains a rate of 42.86mmol g-1 h-1. This work imparts valuable insights for the design of dual co-catalysts, anisotropy-driven spatial vectorial charge separation and migration, and the analysis of migration pathways of photogenerated carriers.

Study on the performance of g-C3N4 composite TiO2 photocatalyst

In order to develop an efficient photocatalyst to solve the environmental pollution problem, in this work, g-C3N4 nanosheets were mixed with TiO2 by mechanical stirring method to successfully construct a binary composite photocatalyst C/T. After a series of test characterization analysis, the C/T composite photocatalyst degraded rhodamine B, and the degradation rate reached 99.4 % after 60 min of reaction. The binary composite formed a new nanoflower structure, which reduced the band gap value of the C/T composite photocatalyst to 2.20 V and promoted the separation efficiency of photogenerated electron-hole pairs and increased the number of active sites, so the photocatalytic performance of C/T was greatly enhanced. The capture measurement experiment was also carried out to determine that the degradation of pollutants by C/T mainly depended on two active substances, ·O2-and h+.

Ni(OH)2 Nanosheet as an Efficient Cocatalyst for Improved Photocatalytic Hydrogen Evolution over Cd0.9Zn0.1S Nanorods under Visible Light.

Loading cocatalysts to promote spatial charge separation has been confirmed as an effective method for improving photocatalytic hydrogen production. This article reports that the synthesis of Ni(OH)2/Cd0.9Zn0.1S nanorod photocatalyst is suitable for photocatalytic H2 generation under visible light. It can be proven that the binary photocatalyst exhibits a one-dimensional nanorod morphological structure. Ni(OH)2 nanosheets occupy the top area of Cd0.9Zn0.1S nanorods. The photocatalytic H2 production rate can reach 132.93 mmol·h-1·g-1, which corresponds to an apparent quantum efficiency of up to 76.5% at a wavelength of 460 nm. In addition, the Ni(OH)2 nanosheet can aggregate the light-incited electrons of Cd0.9Zn0.1S, inhibiting the confluence of electrons and holes. The detailed analysis of its mechanism through characterization methods such as photoluminescence and electrochemical measurement shows that the significant improvement in photocatalytic performance derives from the effective spatial separation of photo-induced charge carriers. Therefore, this synthesis strategy of one-dimensional materials may bring new prospects for more efficient, stable, and sustainable photocatalysis for water splitting.

Multi-synergies of hollow CdS cubes on MoS2 sheets for enhanced visible-light-driven photocatalysis

Formation of intimate interfaces in semiconductor-based heteronanostructures (HNSs) is widely adopted to enhance the efficiency of photocatalytic hydrogen evolution via water splitting because of their efficient light harvesting, charge carrier separation, and transfer capability originating from intimate interface. Here, we employ a multi-step approach, involving the direct growth of the photocatalytically active semiconductor (Cu2O) on MoS2 sheets, along with anion exchange and cation exchange methods to design hollow CdS cube/MoS2 sheet HNSs (H-CdS/MoS2 HNSs) consisting of intimate interfaces between hollow CdS cubes and MoS2 sheets. These distinctive morphological and compositional features endow H-CdS/MoS2 HNSs with exceptional charge transfer capability, intrinsic catalytic activity, and light-harvesting capacity. Consequently, H-CdS/MoS2 HNSs demonstrate significantly enhanced photocatalytic performance and stability for hydrogen evolution reactions and pollutant degradation under visible light irradiation compared to their binary and unary photocatalyst counterparts. This design strategy demonstrates the significance of forming intimate interfaces using hollow semiconductors in HNSs for advanced photocatalysis.

Rational design of Bi2Sn2O7/Bi5O7I S-scheme heterojunction for visible photocatalytic oxidation of emerging pollutants

The construction of an S-scheme heterostructure is considered as a promising strategy for enhancing photocatalytic performance. Herein, a three-dimensional Bi5O7I (BOI) microsphere decorated with Bi2Sn2O7 (BSO) nanoparticles was prepared for the first time via a simple ultrasonic-assisted electrostatic self-assembly strategy and used for the degradation of 2,4-dinitrophenylhydrazine. 3 wt% Bi2Sn2O7/Bi5O7I has the highest degradation activity (93.7 %), with an apparent rate constant of 0.0848 min−1, which is 2.55 times that of the original Bi5O7I (0.0333 min−1). Moreover, the optimal binary heterojunction photocatalyst has good reusability and universal applicability. The results of cyclic voltammetry tests clarify that the optimal photocatalyst can provide more surface reactive sites. The results of radical trapping experiments and electron spin resonance indicate that holes (h+) and superoxide radicals are the main active radicals in the degradation process of 2,4-dinitrophenylhydrazine. Photoelectrochemical and photoluminescence confirm that 3 wt% Bi2Sn2O7/Bi5O7I composites exhibit the highest separation rate of photogenerated carriers. Finally, based on the results of experimental studies and theoretical calculations, the S-scheme charge transfer path on Bi2Sn2O7/Bi5O7I composite is determined. This work provides a new perspective on how to design high-performance S-scheme bismuth oxyhalide-based heterojunction photocatalysts for solar energy conversion.

Insights into the performance of binary heterojunction photocatalysts for degradation of refractory pollutants.

The uncontrolled discharge of industry- and consumer-derived micropollutants and synthetic contaminants into freshwater bodies represents a severe threat to human health and aquatic ecosystem. Inexpensive and highly efficient wastewater treatment methods are, therefore, urgently required to eliminate such non-biodegradable, recalcitrant, and toxic organic pollutants. In this context, advanced oxidation processes, particularly heterogenous photocatalysis, have received enormous attention over the past few decades. Among the different classes of photocatalysts explored by the scientific community, heterojunction photocatalysts, in general, and binary heterojunction photocatalysts, in particular, have shown tremendous promise, attributed to their many distinct advantages. As such, the present review highlights the application of diverse array of binary heterojunction photocatalysts for eliminating water-borne contaminants. Specifically, a bibliometric analysis has been conducted to identify the ongoing research trend and future prospects of heterojunction photocatalysts. It appears that metal oxide/metal oxide-based heterojunctions have superior thermal and mechanical stability compared to other heterojunction photocatalysts. In contrast, metal oxide/non-metal semiconductor-based heterojunctions are extremely effective in pollutant degradation without significant leaching of metal ions. The review concludes by proposing novel strategic research guidelines in order to make further advances in this rapidly evolving cross-disciplinary field of topical interest.

Carbon-based binary organic photocatalysts for rapid dye degradation under weak light: performance and mechanistic study

Congo red (CR), a stable benzidine diazo dye due to its azo bonds, resists natural photodegradation and poses a significant ecological threat.

CdS QDs grown on ellipsoidal BiVO4 for efficient photocatalytic degradation of tetracycline.

Designing efficient, inexpensive, and stable photocatalysts to degrade organic pollutants and antibiotics has become an effective way for environmental remediation. In this work, we successfully performed in situ growth of CdS QDs on the surface of elliptical BiVO4 to try to show the advantage of the binary heterojuncted photocatalyst (BVO@CdS) for the photocatalytic degradation of tetracycline (TC). The In situ growth of CdS QDs can provide a large number of reactive sites and also generate a larger contact area with BiVO4. In addition, compared with mechanical composite materials, in situ growth can significantly reduce the energy barrier at the interface between BiVO4 and CdS, providing more channels for the separation and migration of photogenerated charge carriers, and further improving reaction activity. As a result, BVO@CdS-0.05 shows the best degradation efficiency, with a degradation rate of 88% after 30 min under visible light. The TC photodegradation follows a pseudo-second-order reaction with a dynamic constant of 0.472 min-1, which is 6.47 times that of pure BiVO4, 7.24 times that of pure CdS QDs and 2 times that of the mechanical composite. The degradation rate of BVO@CdS-0.05 decreases to 77.8% with a retention rate of 88.5% after four cycles, demonstrating excellent stability. Through liquid chromatography-mass spectrometry (LC-MS) analysis, two possible pathways for TC degradation are proposed. Through free radical capture experiments, electron spin resonance measurements, and photoelectrochemical comprehensive analysis, it is confirmed that BVO@CdS composites have constructed an efficient Z-scheme heterojunction via in situ growth, thereby highly enhancing the separation and transport efficiency of charge carriers.

Facile in situ construction strategy to deposit Mn0.5Cd0.5S nanoparticles on TiO2 nanosheets for highly efficient visible light photocatalytic degradation of tetracycline

A novel binary photocatalyst Mn0.5Cd0.5S/TiO2 consisting of Mn0.5Cd0.5S nanoparticles and TiO2 nanosheets was designed and constructed by a two-step hydrothermal method with high-efficiency visible-light photocatalytic performance.

Construction of ZnCdS/TiO2 Z-Scheme heterostructure with excellent photocatalytic performance for degradation of norfloxacin

In this study, the binary heterojunction photocatalyst of ZnCdS modified TiO2 nanorod arrays was successfully prepared by hydrothermal method and successive ionic layer adsorption and reaction (SILAR). The ZCST-12 showed high removal efficiency (93.1%) of norfloxacin (NOR) within 90 min. The rate constant Kα was 0.0278 min−1 and the transient photocurrent density of ZCST-12 was up to 63 μA/cm2, which were 3.08 and 3.7 times higher than that of unmodified TiO2. The synergistic effect of ZnCdS and TiO2 broadens the range of light absorption, makes the absorption edge red shift, and greatly improves the light absorption and utilization ability of the material. The ZnCdS/TiO2 Z-scheme heterojunction greatly promotes the separation of electrons and holes and accelerates the carriers transport, preserves the strong redox ability of spatially separated holes and electrons, and effectively improves the photocatalytic performance. This study provides a simple method for preparing ZnCdS/TiO2 heterojunction photocatalyst.

Preparation of CeO2-WO3 binary heterojunction photocatalyst for sustainable tetracycline degradation: Optimization of synthesis and degradation conditions, characterization, transformation pathway, and dominant reactive species

Tetracycline (TC) is a widely utilized antibiotic recognized for its potential consequences on human health. Herein, a novel photocatalyst, CeO2-WO3 nanocomposite, was synthesized through a sufficient and cost-effective technique, and subsequently subjected to comprehensive characterization including XPS, XRD, SEM, TEM, FTIR, and BET. The optimal photocatalyst based on its performance in TC degradation was achieved at CeO2 content ranging from 5 to 25 wt. % and calcination temperature ranging from 300 to 600°C, using Response Surface Methodology (RSM). The optimal synthesis condition obtained from the Design of Experiments (DoE) was CeO2 content of 16.25 wt. % and calcination temperature of 444.37°C. In addition, the effect of four affecting variables, including TC concentration, pH, catalyst dose, and irradiation time was investigated and TC degradation of 94.28 % was attained at optimum conditions (i.e., TC initial concentration: 20.04 mg/L, pH: 6.88, catalyst dose: 0.19 g/L, and irradiation time: 94.90 min). The synthesized photocatalyst demonstrated a significant removal of chemical oxygen demand (COD) by 79.42 % in TC mineralization, showing notable efficacy compared to previous investigations. Hydroxyl (•OH) and superoxide (•O2−) radicals were found to be robust active agents, owing to their indiscriminate oxidation capabilities through scavenger tests and ESR analysis. Additionally, LC-Mass analysis was employed to elucidate the intermediates generated during the photodegradation of TC, resulting in the formulation of a plausible degradation pathway. Overall, the CeO2-WO3 photocatalyst demonstrated commendable resistance, enduring through five cycles with minimal cerium leaching, thereby accentuating its efficacy in the decomposition of antibiotics.

Recent updates on g-C3N4/ZnO-based binary and ternary heterojunction photocatalysts toward environmental remediation and energy conversion

Background: The utilization of photocatalytic materials has garnered significant consideration due to their distinctive properties and diverse applications in environmental remediation and energy conversion. In photocatalysis, several wide and narrow band gap photocatalysts have been discovered. Amongst several photocatalysts, g-C3N4 photocatalyst is becoming the interest of the research community due to its unique properties. But as a single photocatalyst, it is inherited with certain confines for instance higher photocarrier recombination rate, lower quantum yield, low specific surface area, etc. However, the heterojunction formation of g-C3N4 with other wide band gap photocatalysts (ZnO) has improved its photocatalytic properties by overcoming its limitations.
 Methods: The synergistic interaction amid g-C3N4 and ZnO photocatalysts enhanced optoelectrical properties superior mechanical strength and improved photocatalytic activity. The nanocomposite exhibits excellent stability, high surface area, efficient separation, and migration of photocarriers, which are advantageous for applications in photocatalytic energy conversion and environmental remediation. The g-C3N4-ZnO nanocomposite represents a material comprising g-C3N4 and ZnO photocatalysts which exhibit a broad absorption range, efficient electron-hole separation, and strong redox potential. The combination of these two distinct materials imparts enhanced properties to the resulting nanocomposite, making it suitable for various applications. Henceforth, current review, we have discussed the photocatalytic properties of g-C3N4 and ZnO photocatalysts and modification strategies to improve their photocatalytic properties.
 Significant Findings: This article offers an inclusive overview of the g-C3N4-ZnO-based nanocomposite, highlighting its photocatalytic properties and potential applications in several pollutant degradation and energy conversion including hydrogen production and CO2 reduction.

Unleashing the power of solar light: WO3 nanorods decorated onto BiVO4 dendrites for tetracycline detoxification and water splitting.

The coupling of different oxide materials in a nanohybrid enables the customization of their optical and charge transport properties, leading to improved interfacial charge segregation and migration. In this study, BiVO4/WO3 (BVW), a sunlight-driven photocatalyst with distinct mole ratios was synthesized via a facile hydrothermal approach. The resultant catalyst exhibits a nanorods shape morphology decorated onto dendrite-like matrix and is studied for photocatalytic elimination of tetracycline (TC) and photoelectrocatalytic (PEC) H2 production. The effect of illumination time, solution pH, photocatalyst concentration, and mole ratios of BiVO4 to WO3 on the photocatalytic abatement of TC were tested sequentially as effective operating factors. Under optimal condition, 3:1 BiVO4:WO3 (31BVW) nanohybrid demonstrated a maximum degradation efficacy of 96.2% (rate constant ~0.0241 min-1), which is much better than its individual components and commercial TiO2-P25 (50.9%). The resultant by-products of TC decomposition were analyzed using GC-MS to explain the degradation mechanism. Moreover, as a photoanode, 31BVW showed a high photocurrent density of 0.64 mA/cm2 at 1.23 V vs RHE and a steady photocurrent for ~6 h under chronoamperometry study at1.23 V vs RHE. However, bare BiVO4 and WO3 exhibited the photocurrent density of 0.001 mA/cm2, and 0.015 mA/cm2, respectively at 1.23 V vs RHE. The Mott-Schottky analysis of 31BVW confirms their n-type behavior, with a calculated flat band potential of -0.067 V. The hydrogen production rate was theoretically calculated as 4.56 mmolcm-2 s-1 from chronoamperometric measurements. The photocatalyst's efficacy in TC degradation was further established via its reusability upto 7 cycles. Post degradation characterization of catalyst confirms its stability in lieu of practical usage. Comparative studies with existing literature revealed the superiority of reported photocatalysts in both applications. Overall, the binary BVW photocatalyst shows great potential for removing detrimental contaminants as well as H2 production via PEC water splitting due to efficient charge separation, reduced recombination, high surface area, and widen absorption window of the nanohybrid.

A directional built-in electric field assisted 2D/1D g-C3N4/CeO2 S-scheme heterojunction for efficient RhB degradation and highly-selective CO2 photoreduction

This study synthesized a well-designed 2D/1D g-C3N4/CeO2 visible-light-driven photocatalyst through a straightforward approach. The binary photocatalyst emerged remarkable photo-degradation performance with a removal rate of 99.07% towards RhB in 120min and the k value of 0.0361 min−1, which maintained over 95% in four cycles. Fascinatingly more, highly-active converting CO2 to CH4 instead of CO during CO2 photo-reduction. The yield rate of CH4 reached 14.63 µmol·g−1·h−1, which was 26.13 folds than the CO generation rate (0.56 µmol·g−1·h−1). Moreover, the CH4 yield rate of g-C3N4/CeO2 heterojunction was 22.4 and 20.9 times improvement in comparison with pristine CeO2 nanorods and CN nanosheets, respectively. On account of HPLC-MS, ESR, active species scavenger investigation, and accurate energy-band structure analysis, a possible RhB degradation mechanism over 2D/1D g-C3N4/CeO2 heterojunction was elucidated. Meanwhile, an S-scheme mechanism with a built-in electric field was illuminated, which helped understand the preeminent photocatalytic performance. This research offers systematic insights into the preparation, activity, and mechanism of g-C3N4-based photocatalysts for environmental purification projects.

Enhanced photocatalytic degradation of imidacloprid by a simple Z-type binary heterojunction composite of long afterglow with metal-organic framework

Imidacloprid (IMC) is a widely used nicotine-based pesticide that can cause severe harm to water resources. To address this issue, a simple binary heterojunction photocatalyst was constructed to degrade IMC under visible light. Furthermore, the catalyst was able to continue degrading approximately 15% of IMC within 5 h under dark. The possible photocatalytic degradation intermediate's structure and low toxicity were verified by mass spectrometry and zebrafish embryo experiments, respectively. The catalyst also exhibited good stability. Therefore, a simple photocatalyst with excellent performance and low toxicity of degradation products was successfully developed for IMC pesticide removal in water.

Enhanced photocatalytic reduction of CO2 using a novel 2D/0D SnS2/CeO2 binary photocatalyst with Z-scheme heterojunction and oxygen vacancy

In this work, suitable band gap width, strong photo-response to visible light, and a high photogenerated carrier density offered by an important member of layered sulfides, SnS2, were kept in view for designing and producing a highly effective photocatalyst for CO2 reduction. Hence, SnS2/CeO2 heterojunction composite photocatalysts were triumphally fabricated by a facile in situ hydrothermal synthesis method, combining advantages of the built-in electric field and oxygen vacancies of two materials. Various characterization techniques were exploited to scrutinize the photocatalyst’s structure and confirm that the carrier transport efficiency and photocatalytic performance are enhanced by the synergistic impact of the heterojunction structure and presence of oxygen vacancies. Owing to the successful loading of zero-dimensional CeO2 nanoparticles onto two-dimensional SnS2 nanosheets, the 2D/0D structure improves the photo-response range of the composites and provides faster electron transfer rates. The composite material maintained the hydrophobic characteristic of single SnS2, while inhibiting the hydrophilic property of single CeO2. As a result, CO and CH4 yields of prepared binary Z-type heterojunction photocatalysts are 24.6 and 4.4 folds higher than those of single SnS2, respectively. This innovative study will contribute to exploration of SnS2-based photocatalytic materials and provide a new feasible direction for light energy-driven CO2 reduction.

Photocatalytic reduction of CO2 in aqueous phase using amino-functionalized MOFs loaded with hydroxy-functionalized graphene quantum dots

Hydroxy-functionalized graphene quantum dots (OH-GQDs) were loaded onto NH2-MIL-101(Fe) to prepare a novel binary OH-GQDs/NH2-MIL-101(Fe) (OGNM) composite with a simple solvothermal method. The obtained catalysts were characterized by SEM, TEM, XRD, FI-IR, XPS and BET to analyze the morphology, elemental composition, and specific surface area of the composite material. Notably, the morphology and micro-structures of OGMM-3 exhibited that OH-GQDs evenly dispersed on the surface of hexagonal micropillar NH2-MIL-101(Fe). The nanocomposite catalysts were tested in a photocatalytic CO2 reduction system using water and acetonitrile as solvents, without additional sacrificial agents. OGNM-3 composite possessed the optimum photoreduction CO2 activity, with a CO yield of 128.68 μmol·g−1 within 10 h, which was 5.3 times higher than that of pure NH2-MIL-101(Fe). After three cycles of reuse, the catalyst still maintained catalytic activity without any significant changes in its crystal structure, morphology or functional groups. In summary, this study proposed a design for synthesizing binary OGNM photocatalysts, offering useful insights for cost-effectively address CO2 emissions in greenhouse gas emissions.

An experimental design study of photocatalytic activity of the Z-scheme silver iodide/tungstate binary nano photocatalyst.

A binary AgI/ Ag2WO4 photocatalyst was fabricated and characterized by SEM, XRD, UV-Vis DRS, and FT-IR. It was then used to photodegrade sodium ceftriaxone (CTX) in an aqueous solution. The band gap energies of 2.95, 2.78, and 2.62eV were obtained by the Kubelka-Munk model for Ag2WO4, AgI, and AgI/Ag2WO4 catalysts. The samples have pHPZC values of 6.9, 4.2, and 6.6, respectively. The synergistic photocatalytic activity of the coupled system depended on the AgI:Ag2WO4 mole ratio and grinding time (optimums:mole ratio of 4:1 and time 30min). The experimental design was used for optimizing the conditions and a quadratic model well-processed the data based on the model F value of 131.87 > F0.05,14,13 = 2.55 and LOF F value of 0.78 < F0.05,10,3 = 8.78. The optimized RSM run included the irradiation time of 85min, 3.5mg/L of CTX sample at pH 9, and a catalyst dose of 1.0g/L. Under the optimized conditions, about 63% of CTX molecules were photodegraded. In the study of the scavenging agents, the direct Z-scheme mechanism accumulated electrons in the CB-AgI and the holes in the VB-Ag2WO4 level, as stronger reducing and oxidizing centers than the accumulated electrons and holes of the type (II) heterojunction mechanism. Compared to a CTX oxidation potential of about 0.06V, the direct Z-scheme mechanism is more favorable to reduce or oxidize it.

Photocathodic protection performance of a nonmetal ternary heterojunction for 304 stainless steel

Photocatalytic materials are important in extensive applications including photocathodic protection. Herein, we report a nonmetal ternary photocatalyst graphitic carbon nitride/reduced graphene oxide/polypyrrole (g-C3N4/rGO/PPy) fabricated by thermal polymerization. Transmission electron microscope (TEM), X-ray diffractometer (XRD), Fourier transform infrared (FTIR), and photoluminescence spectra (PL) were used to analysis the microstructures, crystalline structures, chemical constitutions, and electronic structures of the g-C3N4, g-C3N4/rGO, and g-C3N4/rGO/PPy. The ternary photocatalyst exhibits superior photocathodic protection performance compared with that of the pristine and binary photocatalyst. These results will be pivotal to progress in photocathodic protection employing nonmetal photocatalyst materials.

Effective graphene incorporation of strontium niobate–doped titanium oxide for photocatalytic hydrogen production

To meet the increasing global demand for clean energy and mitigate the impact of CO2 emissions on climate change, the production of photocatalytic hydrogen through water splitting is a compelling scientific and technological objective. Despite considerable efforts, the establishment of a reliable and highly efficient system for hydrogen generation powered by visible light remains challenging. In this study, we developed a solar-active strontium niobate-doped titanium oxide incorporated with graphene (Sr2Nb2O7–rGO–TiO2), characterized by various analytical techniques such as optical, morphological, HR-TEM, XPS, and XRD. Sr2Nb2O7–rGO–TiO2 demonstrated enhanced photocatalytic H2 evolution under solar irradiation without requiring precious-metal doping. The maximum H2 production performance rate of 1769 μmol/g/h was attained with the Sr2Nb2O7–rGO–TiO2 composites, significantly surpassing those of the bare (TiO2: 210 μmol/g/h, Sr2Nb2O7: 88 μmol/g/h) and binary (TiO2–rGO: 430 μmol/g/h, Sr2Nb2O7–rGO: 176 μmol/g/h, and Sr2Nb2O7–TiO2: 880 μmol/g/h) photocatalysts. The enhanced performance of the Sr2Nb2O7–rGO–TiO2 composite is attributable to the synergistic effect of rGO acting as an electron-transfer bridge. Thus, with the integration of rGO, absorption is attainable in an extended range up to 445 nm (2.90 eV), suggesting that the composite material could enable the catalyst to absorb more visible light. Additionally, the composite exhibited minor degradation after five consecutive cycles, demonstrating its excellent stability and reusability for hydrogen generation. Based on a comprehensive evaluation of the ESR and transient photocurrent response, a potential Z-scheme mechanism for the photocatalytic H2 generation activity over Sr2Nb2O7–rGO–TiO2 was suggested. The Z-scheme processability allows more electrons to contribute to the H2 evolution reduction. In this study, we developed a non-toxic, cost-effective, highly efficient, and recyclable photocatalyst for H2 production.