In2S3 nanoflakes grounded in Bi2WO6 nanoplates: A novel hierarchical heterojunction catalyst anchored on W mesh for efficient elimination of toluene.

Toxic toluene can be completely oxidized in CO2 and H2O with novel three-dimensional (3D) In2S3@Bi2WO6 hierarchical crystals under visible light. Dense and uniform In2S3 nanoflakes are rooted in Bi2WO6 nanoplates which intercross with each other and are anchored on a pliable tungsten mesh. This leads to the construction of a stable and porous interface for adsorbing and decomposing target gaseous toluene. The firm contact between In2S3 and Bi2WO6 initiates the formation of a built-in electric field that helps in channeling the photogenerated electrons in Bi2WO6 CB to quench the holes in2S3 VB. This results in highly capable electrons and holes, as well as notable increase in the yields of •O2- and •OH. 99.7% of toluene is removed and 93.4% is converted to CO2 when it is degraded in simulated air. This validates its remarkable efficacy in detoxifying toluene.

Atomic-Level and Modulated Interfaces of Photocatalyst Heterostructure Constructed by External Defect-Induced Strategy: A Critical Review.

Despite the existence of numerous photocatalyst heterostructures, their separation efficiency and charge flow precision remain low due to the poor study on interfacial properties. The photocatalysts with confined defects can effectively control the photogenerated carrier migration, but the metastability of such defects considerably decreases the photocatalyst stability. Meanwhile, the introduction of defective region can increase the coordinative unsaturation and delocalize local electrons to promote their interactions with the molecules/ions in that region. The selective growth of modulated heterogeneous interface by defect-induced strategy may not only increase the stability of defective structures, but also enhance the migration of interfacial charges. Using this method, photocatalytic heterostructures with low contact resistances and intimate interfaces are constructed to achieve the optimal charge migration in terms of efficiency and accuracy. In this work, the point, linear, and planar heterogeneous interfaces and related defect engineering techniques are discussed. Particularly, it is focused on the external, defect-induced interfacial heterogeneities with various spatial and dimensional configurations, which exhibit modulated and controllable interfacial properties. Furthermore, the main aspects of fabricating photocatalyst heterostructures by the defect-induced strategy, including the i) controllable generation of defects, ii) advanced characterization methods, and iii) elaborate construction of the minimal interface, are described.

Self-Optimization of the Active Site of Molybdenum Disulfide by an Irreversible Phase Transition during Photocatalytic Hydrogen Evolution.

The metallic 1T-MoS2 has attracted considerable attention as an effective catalyst for hydrogen evolution reactions (HERs). However, the fundamental mechanism about the catalytic activity of 1T-MoS2 and the associated phase evolution remain elusive and controversial. Herein, we prepared the most stable 1T-MoS2 by hydrothermal exfoliation of MoS2 nanosheets vertically rooted into rigid one-dimensional TiO2 nanofibers. The 1T-MoS2 can keep highly stable over one year, presenting an ideal model system for investigating the HER catalytic activities as a function of the phase evolution. Both experimental studies and theoretical calculations suggest that 1T phase can be irreversibly transformed into a more active 1T' phase as true active sites in photocatalytic HERs, resulting in a "catalytic site self-optimization". Hydrogen atom adsorption is the major driving force for this phase transition.

Converting formaldehyde in methanol with MoO2 under irradiation: A pollution-free strategy for cleaning air.

Direct photocatalytic reduction of toxic formaldehyde (HCHO) in value-added chemicals and fuels is promising because that not only abates the environmental pollution, but also solves the energy shortage. Herein, self-supported MoO2 and MoO3 nanoparticles growing on Mo meshes were comparatively applied to the photocatalytic conversion of HCHO. Under UV-visble lights, MoO2 reduces HCHO in methanol (CH3OH) while MoO3 oxidizes HCHO in carbon oxide and water. Their contrary photocatalytic capacities were revealed. Compared with MoO3, the lower work function of MoO2 enables an electron-rich interface, realizing a complete reduction of 30 ppm HCHO to CH3OH in 30 min. Theoretical calculations clarify that a large number of delocalized electrons on MoO2 attracts HCHO molecule and activates its CO bond, facilitating subsequent hydrogenation and reduction of HCHO to CH3OH. As for MoO3, the wider bandgap and higher potential of valence band govern the photocatalytic oxidation of HCHO.

Zeolitic imidazolate framework-8 for ratiometric fluorescence sensing tetracyclines in environmental water based on AIE effects.

A ratiometric fluorimetric sensing strategy with Zeolitic imidazolate framework-8 (ZIF-8) has been developed for the analysis of tetracycline (TC) in environmental water samples. ZIF-8 with polyhedral structure was synthesized at room temperature exhibiting blue fluorescence at 445 nm. Especially, the as-prepared ZIF-8 could conduct the aggregation-induced emission (AIE) effect in the presence of TC through electrostatic, hydrogen bond, π-π stacking, and coordination interactions. As a result, a strong yellow-green fluorescence appeared and a new fluorescence peak at 505 nm was observed, although the initial fluorescence peak at 445 nm of ZIF-8 was almost unchanged. A ZIF-8-based fluorimetric platform was thereby designed for sensing TC by using ZIF-8 as the fluorescent probe with the peak at 445 nm as the reference and the one at 505 nm as the changing signal, which should increase with the increasing concentrations of TC. Moreover, the quantitative analysis of TC could be carried out through the ratiometric peak intensities of F505/F445, with a detection limit as low as 14.7 nM. Additionally, the ratiometric fluorescent analysis method was successfully employed to detect TC in environmental water samples, indicating that ZIF-8 might be a good luminescent sensor for probing the pollutants in the environmental water.

High-throughput lateral and basal interface in CeO2@Ti3C2TX: Reverse and synergistic migration of carrier for enhanced photocatalytic CO2 reduction.

Rational construction of heterogeneous interfaces that maximize carrier flux and allow carrier separation for achieving efficient photocatalytic CO2 reduction still remain a challenge. In this work, high-throughput and intimate interfaces that allow efficient carrier separation and flux are designed by depositing high-density CeO2 nanoparticles on large-area Ti3C2TX (T = terminal group) nanosheets. Oxygen-containing functional groups of Ti3C2TX nanosheets facilitate the anchoring of CeO2 nanoparticles on the nanosheets via the formation of interfacial Ce-O-Ti bonds, which serve as effective channels for reverse and synergistic migration of electrons and holes to achieve spatial separation. The light absorption of the CeO2@Ti3C2TX composites is extended to the infrared (IR) region due to narrow bandgaps of Ti3C2TX. High-density lateral and basal interfaces enhance carrier migration, which ultimately aids the CeO2@Ti3C2TX composites to exhibit excellent activity for reducing CO2 to alcohols (i.e., methanol and ethanol) under both visible (vis) and IR irradiations. The total amount of produced alcohol under visible irradiation is 109.9 µmol•gcatal-1 (methanol and ethanol: 76.2 and 33.7 µmol•gcatal-1, respectively), which is 4.3 times higher than that obtained using CeO2 (methanol and ethanol: 19.8 and 6 µmol•gcatal-1, respectively). The yields of methanol and ethanol using the optimized CeO2@Ti3C2TX were 102.24 and 59.21 µmol•gcatal-1, respectively, after 4 h under the vis-IR irradiation.

Hierarchical Ag3PO4@ZnIn2S4 nanoscoparium: An innovative Z-scheme photocatalyst for highly efficient and predictable tetracycline degradation.

Z-scheme photocatalyst preserved with superior oxidicability is an innovative photocatalyst system that can be used for efficient photocatalytic detoxification of antibiotics. In this study, Z-scheme Ag3PO4@ZnIn2S4 photocatalyst was constructed by decorating Ag3PO4 nanoparticles on ZnIn2S4 nanoscopariums. ZnIn2S4 nanoscopariums were prepared by self-templated strategy and given hierarchical structures. The hierarchical Ag3PO4@ZnIn2S4 provides more active sites for generating photogenerated carriers and large surface area for capturing tetracycline. The study results show that Ag3PO4@ZnIn2S4 performed excellently well in the photocatalytic degradation of tetracycline and also in protecting Ag3PO4 nanoparticles from photo-corrosion. The highest removal efficiency (up to 92.3%) was achieved from the optimal composites of Ag3PO4 and ZnIn2S4. In stability tests, Ag3PO4@ZnIn2S4 did not reduce the photocatalytic activity of degrading tetracycline after five successive runs. Active radical identification proves that the transfer behavior of electron and hole over Ag3PO4@ZnIn2S4 follows a direct Z-scheme mechanism. Furthermore, the transformation pathway for degrading tetracycline was proposed by combining the Fukui index prediction with Mass Spectra identification of intermediates. This work presents in-depth sights into a regulated degradation pathway from theoretical prediction and practical identification based on innovative Z-scheme photocatalyst.

Gradient Hydrogen Migration Modulated with Self-Adapting S Vacancy in Copper-Doped ZnIn2S4 Nanosheet for Photocatalytic Hydrogen Evolution.

It is a challenge to regulate charge flow synergistically at the atomic level to modulate gradient hydrogen migration (H migration) for boosting photocatalytic hydrogen evolution. Herein, a self-adapting S vacancy (Vs) induced with atomic Cu introduction into ZnIn2S4 nanosheets was fabricated elaborately, which can tune charge separation and construct a gradient channel for H migration. Detailed experimental results and theoretical simulations uncover the behavior mechanism of Vs generation with Cu introduction after substituting a Zn atom tendentiously. Cu-S bond shrinkage and Zn-S bond distortion are presented around Vs areas. Besides, Vs induced by Cu introduction lowers the internal electric field to restrain electron transmission between layers, which are enriched on the Vs area because of the lower surface electrostatic potential. Atomic Cu and Vs show a synergistic effect for regulating regional charge separation due to the Cu dopant being a hole trap and Vs being an electron trap. The channels for H migration with gradient ΔGH0 are constructed by different S atom sites, which are modulated by Vs. Gradient H migration driven by a photothermal effect occurs on an identical surface without striding across a heterogeneous interface, which is a valid pathway with lower resistance for boosting H2 release. Ultimately, 5 mol % Cu confined in ZnIn2S4 nanosheets achieves an optimum photocatalytic hydrogen evolution activity of 9.8647 mmol g-1 h-1, which is 14.8 times higher than 0.6640 mmol g-1 h-1 for ZnIn2S4, and apparent quantum efficiency reaches 37.11% at 420 nm. This work demonstrates the behavior mechanism of atomic substitution and provides cognition for hydrogen evolution mechanism deeply.

Self-assembly Cu2O nanowire arrays on Cu mesh: A solid-state, highly-efficient, and stable photocatalyst for toluene degradation under sunlight.

Sunlight driven photocatalysis offers an effective and eco-friendly technology for volatile organic compounds (VOCs) removal. Three dimensional (3D) and oriented structure can facilitate efficient photon absorption and rapid diffusion of VOCs, which prevails over the powder-formed catalysts. Herein, free-standing and uniform p-type Cu2O nanowire (NW) arrays were obtained through heat treatment of Cu(OH)2 NWs, which were spontaneously grown from Cu mesh in air under room temperature for the first time. The as-prepared Cu2O NWs show excellent degradation performance in decomposing 30 ppm toluene (99.9 % within 120 min) and high stability (no decline after ten recycles). The toluene degradation was also conducted under the natural sunlight, demonstrating complete removal from 12:00 am to 15:00 pm. During photocatalysis, toluene is attacked by the photogenerated holes (h+) and hydroxyl radicals (·OH), and finally oxidized to nontoxic small molecules. The photocatalytic removing toluene with Cu2O NWs/Cu mesh has a promising application prospect owing to its low cost, high efficiency, stability, and convenient operation.

Design and synthesis of robust Z-scheme ZnS-SnS2 n-n heterojunctions for highly efficient degradation of pharmaceutical pollutants: Performance, valence/conduction band offset photocatalytic mechanisms and toxicity evaluation.

Petal-like ZnS-SnS2 heterojunctions with Z-scheme band alignment were prepared by one-pot solvothermal strategy. The optimal (1:1) ZnS-SnS2 can degrade 93.46 % of tetracycline and remove 73.9 % COD of pharmaceutical wastewater under visible-light irradiation due to the efficient production of H, O2-, h+ and OH. The toxicity evaluation by ECOSAR prediction and the growth of E. coli indicates efficient toxicity reduction of tetracycline by photocatalysis and the non-toxicity of ZnS-SnS2. The attacked sites on tetracycline by reactive species were analyzed according to Fukui index, and two degradation pathways of tetracycline were inferred via the identification of intermediate products. Tetracycline degradation efficiency and the energy consumption in different water bodies were compared, and it was found that the electrical energy per order (EE/O) was the lowest in Ganjiang River. The valence band offset (ΔEVBO) and conduction band offset (ΔECBO) of ZnS-SnS2 were 1.02 eV and 0.22 eV, respectively. The probable photocatalytic mechanism of ZnS/SnS2 heterojunctions with Z-scheme band alignment based on ΔEVBO and ΔECBO was first presented.

Bi2MoO6 Quantum Dots In Situ Grown on Reduced Graphene Oxide Layers: A Novel Electron-Rich Interface for Efficient CO2 Reduction.

Bi2MoO6 quantum dots (BM QDs, 5 nm in diameter) are evenly in situ grown on reduced graphene oxide (rGO) layers, sensitizing the graphene with high visible light response and activity for efficient solar light-driven CO2 reduction. Under irradiation, small-sized BM QDs generate active electrons and donate them to the rGO layers. Since the formation of BM QDs and the reduction of GO are undergone simultaneously, a close connection between BM QDs and rGO enables the electron injection from excited Bi2MoO6 QDs to graphene scaffolds, and abundant electrons accommodated by the rGO layers offer an electron-rich interface for CO2 reduction. With the benefit of the improved electron extraction and transport over the BM QDs/rGO interface, 84.8 µmol g-1 of methanol and 57.5 µmol g-1 of ethanol are achieved on BM QDs/rGO in 4 h with optimal composition. The total output of alcohols over BM/rGO (142.3 µmol g-1) is 2.2 and 4.4 times that achieved on unmodified Bi2MoO6 QDs (64.0 µmol g-1) and flower-like Bi2MoO6 (32.2 µmol g-1), respectively.

A Critical Review on Energy Conversion and Environmental Remediation of Photocatalysts with Remodeling Crystal Lattice, Surface, and Interface.

Solar energy is a renewable resource that can supply our energy needs in the long term. A semiconductor photocatalysis that is capable of utilizing solar energy has appealed to considerable interests for recent decades, owing to the ability to aim at environmental problems and produce renewal energy. Much effort has been put into the synthesis of a highly efficient semiconductor photocatalyst to promote its real application potential. Hence, we reviewed the most advanced methods and strategies in terms of (i) broadening the light absorption wavelengths, (ii) design of active reaction sites, and (iii) control of the electron-hole (e--h+) recombination, while these three processes could be influenced by remodeling the crystal lattice, surface, and interface. Additionally, we individually examined their current applications in energy conversion (i.e., hydrogen evolution, CO2 reduction, nitrogen fixation, and oriented synthesis) and environmental remediation (i.e., air purification and wastewater treatment). Overall, in this review, we particularly focused on advanced photocatalytic activity with simultaneous wastewater decontamination and energy conversion and further enriched the mechanism by proposing the electron flow and substance conversion. Finally, this review offers the prospects of semiconductor photocatalysts in the following three vital (distinct) aspects: (i) the large-scale preparation of highly efficient photocatalysts, (ii) the development of sustainable photocatalysis systems, and (iii) the optimization of the photocatalytic process for practical application.

Ultrafine Ag@AgI nanoparticles on cube single-crystal Ag3PO4 (1 0 0): An all-day-active Z-Scheme photocatalyst for environmental purification.

Exploring and designing an efficient and robust photocatalyst toward the degradation of organic pollutants under nature sunlight irradiation is a challenging research topic. The ability to maintain the photocatalytic activity in the entire daytime will be the ultimate goal for further widespread application of solar energy-driven semiconductor photocatalysis. Here, an all-day-active Z-scheme photocatalytic system is reported by employing Ag@AgI nanoparticles decorated Ag3PO4 cubes (C-Ag3PO4@Ag@AgI). By coupling the pronounced carrier separation as well as increased stability, the C-Ag3PO4@Ag@AgI is capable of performing efficient Rhodamine B (RhB) and bisphenol A (BPA) degradation under sunlight irradiation, and still persist noticeable activity when the light is very weak. The RhB (20 mg/L, 50 mL) can be completely degraded by C-Ag3PO4@Ag@AgI (30 mg) within 1 h with the average luminous power of 117.5 mW (3.14 cm2). Dramatically, the as-prepared samples can still maintain photocatalytic activity even in a cloudy day (0.2-6.7 mW). This work has offered a valuable concept of continuous pollutant removal under nature sunlight irradiation in the entire daytime, which may serve as a model system for the wide environment applications, such as the removal of low-level pollutants under weak light irradiation.

Fast adsorption of heavy metal ions by waste cotton fabrics based double network hydrogel and influencing factors insight.

Massive consumption of cotton fabrics has brought up a serious problem concerning the waste cotton fabrics (WCFs) disposal. It is widely accepted that if WCFs can be reutilized, there will be great business potentials. Herein, we prepared a double network hydrogel based on WCFs and polyacrylamide (Cellulose/PAM DNHs) for heavy metal removal. The DNHs exhibit fast kinetics that sorption equilibrium is achieved in 5min because of the porous and sheet-like laminar structures they possess. The DNHs also illustrate excellent adsorption property and good reusability. The tandem two columns packed with Cellulose/PAM-3 can effectively process simulated and practical wastewater, and the adsorption discrepancy is negligible after three adsorption-desorption cycles. The treatment volumes of simulated wastewater are 172.5 BV (7935mL), 195 BV (8970mL), and 292.5 BV (13455mL) for Cd(II), Cu(II), and Pb(II), respectively. Furthermore, the treatment volumes of practical industrial wastewater reach 42 BV (1932mL) for Cd(II), 63 BV (2898mL) for Cu(II), and 87 BV (4002mL) for Zn(II), Pb(II) and Fe, respectively. This work provides a new avenue for the combination of WCFs reuse and heavy metal removal, which is of great importance to the construction of resource sustainability and environment-friendly society.

Regionalized and vectorial charges transferring of Cd1-xZnxS twin nanocrystal homojunctions for visible-light driven photocatalytic applications.

In photocatalyst designing, quick recombination of photo-generated electron-hole pairs in the bulk or on the surface of semiconductors is a major limiting factor in achieving high photocatalytic efficiency, which is one of the most knotty scientific issues. For this purpose, a series of Cd1-xZnxS twin nanocrystal (NC) zinc blende/wurtzite (ZB/WZ) homojunctions photocatalysts were synthesized by a facile solvothermal route and innovatively employed in photocatalytic degradation. In sample Cd0.6Zn0.4S, ZB and WZ phases have the largest distribution and closest interconnection at atomic level. The type-II staggered band alignment formed between two phases made photo-generated electrons and holes spatially separated to ZB (away from twin plane) and WZ (to twin plane) regions, and the ordered arrangement of redox reaction's active sites was then realized inside a single semiconductor. Finally, photocatalytic activities of the samples were evaluated by degradation of methylene blue (MB) upon visible light irradiation. The optimal Cd0.6Zn0.4S NCs without any co-catalyst loading showed high photocatalytic activity with degradation efficiency of 95% in 80 min and performed excellent photostability. Furthermore, photocatalytic degradation and electron transfer mechanisms in Cd0.6Zn0.4S twin NCs are studied particularly. Inner twin structure homojunction has provided a new insight into the crystalline phase engineering.

"Dark Deposition" of Ag Nanoparticles on TiO2: Improvement of Electron Storage Capacity To Boost "Memory Catalysis" Activity.

"Memory catalysis" (MC) studies have received appreciable attention recently because of the unique talent to retain the catalytic performance in the dark condition. However, the MC activity is still low owing to the relatively limited electron storage capacity of the present materials. Here, a TiO2@Ag composite was synthesized by a "dark-deposition (DD)" method, which is based on the electron trap effect of TiO2. Unlike traditional photodeposition (PD), an exploration of the morphology and chemical compositions of as-prepared samples shows that DD can inhibit the growth of Ag nanoparticles and the formation of Ag2O, which greatly improve the electron storage capacity. We further demonstrated that the maximum electronic capacity was in the order of TiO2@Ag-DD (1 µmol/mg) > TiO2@Ag-PD (0.35 µmol/mg) > TiO2 (0.11 µmol/mg). Moreover, the enhanced MC activity was confirmed by various degradation experiments. Especially, the use of TiO2@Ag-DD as a round-the-clock catalyst for the degradation of multicomponent pollutants has also been achieved. This strategy opens a door for enhancing the MC activity and reveals that the coupling of photocatalysis and MC may provide a new opportunity for the continuous removal of pollutants in day and night. It also may be extended to other fields, such as energy storage and continuous disinfection.

MoS2 Quantum Dot Growth Induced by S Vacancies in a ZnIn2S4 Monolayer: Atomic-Level Heterostructure for Photocatalytic Hydrogen Production.

It is highly demanded to steer the charge flow in photocatalysts for efficient photocatalytic hydrogen reactions (PHRs). In this study, we developed a smart strategy to position MoS2 quantum dots (QDs) at the S vacancies on a Zn facet in monolayered ZnIn2S4 (Vs-M-ZnIn2S4) to craft a two-dimensional (2D) atomic-level heterostructure (MoS2QDs@Vs-M-ZnIn2S4). The electronic structure calculations indicated that the positive charge density of the Zn atom around the sulfur vacancy (Vs) was more intensive than other Zn atoms. The Vs confined in monolayered ZnIn2S4 established an important link between the electronic manipulation and activities of ZnIn2S4. The Vs acted as electron traps, prevented vertical transmission of electrons, and enriched electrons onto the Zn facet. The Vs-induced atomic-level heterostructure sewed up vacancy structures of Vs-M-ZnIn2S4, resulting in a highly efficient interface with low edge contact resistance. Photogenerated electrons could quickly migrate to MoS2QDs through the intimate Zn-S bond interfaces. As a result, MoS2QDs@Vs-M-ZnIn2S4 showed a high PHR activity of 6.884 mmol g-1 h-1, which was 11 times higher than 0.623 mmol g-1 h-1 for bulk ZnIn2S4, and the apparent quantum efficiency reached as high as 63.87% (420 nm). This work provides a prototype material for looking into the role of vacancies between electronic structures and activities in 2D photocatalytic materials and gives insights into PHR systems at the atomic level.

Photocatalytic wastewater purification with simultaneous hydrogen production using MoS2 QD-decorated hierarchical assembly of ZnIn2S4 on reduced graphene oxide photocatalyst.

It is attractive to photocatalytically purify wastewater and simultaneously convert solar energy into clean hydrogen energy. However, it is still a challenge owing to the relatively low photocatalytic efficiency of photocatalysts. In this study, we synthesized a molybdenum disulfide (MoS2) quantum dot-decorated 3D nanoarchitecture (MoS2QDs) of indium zinc sulfide (ZnIn2S4) and reduced grapheme oxide (MoS2QDs@ZnIn2S4@RGO) photocatalyst using a simple solvothermal method. The RGO promotes the electron transfer, and the highly dispersed MoS2QDs provides numerous catalytic sites. The photocatalytic purification of rhodamine B (RhB), eosin Y (EY), fulvic acid (FA), methylene blue (MB) and p-nitrophenol (PNP) in simulated wastewaters were further tested. The degradation efficiencies and TOC removal were 91% and 75% for PNP, 92.2% and 72% for FA, 98.5% and 80% for MB, 98.6% and 84% for EY, and 98.8% and 88% for RhB, respectively (Corganics = 20 mg/L, Ccatalyst = 1.25 g/L, t = 12 h, Ilight = 3.36 × 10-5 E L-1 s-1). Among these tests, the highest hydrogen production was achieved (45 µmol) during RhB degradation. Both experimental and calculational results prove that lower LUMO (lowest unoccupied molecular orbit) level of organic molecules was available for transferring electrons to catalysts, resulting in more efficient hydrogen production. Significantly, the removal efficiencies of natural organic substances in actual river water reached 76.3-98.4%, and COD reduced from 32 to 16 mg/L with 13.8 µmol H2 production after 12 h.

A bamboo-inspired hierarchical nanoarchitecture of Ag/CuO/TiO(2) nanotube array for highly photocatalytic degradation of 2,4-dinitrophenol.

The optimized geometrical configuration of muitiple active materials into hierarchical nanoarchitecture is essential for the creation of photocatalytic degradation system that can mimic natural photosynthesis. A bamboo-like architecture, CuO nanosheets and Ag nanoparticles co-decorated TiO2 nanotube arrays (Ag/CuO/TiO2), was fabricated by using simple solution-immersion and electrodeposition process. Under simulated solar light irradiation, the 2,4-dinitrophenol (2,4-DNP) photocatalytic degradation rate over Ag/CuO/TiO2 was about 2.0, 1.5 and 1.2 times that over TiO2 nanotubes, CuO/TiO2 and Ag/TiO2, respectively. The enhanced photocatalytic activity of ternary Ag/CuO/TiO2 photocatalyst was ascribed to improved light absorption, reduced carrier recombination and more exposed active sites. Moreover, the excellent stability and reliability of the Ag/CuO/TiO2 photocatalyst demonstrated a promising application for organic pollutant removal from water.