Extended Light Absorption Research Articles

Constructing Rh-Rh3+ modified Ta2O5@TaON@Ta3N5 with special double n-n mutant heterojunctions for enhanced photocatalytic H2-evolution.

A multiple core–shell heterostructure Rh–Rh3+ modified Ta2O5@TaON@Ta3N5 nanophotocatalyst was successfully constructed through nitriding Rh3+-doped Ta2O5 nanoparticles, which exhibited a much higher carrier separation efficiency about one order of magnitude higher than the Ta2O5@Ta3N5 precursor, and thus an excellent visible light photocatalytic H2-evolution activity (83.64 μmol g−1 h−1), much superior to that of Rh anchored Ta2O5@TaON (39.41 μmol g−1 h−1), and improved stability due to the residual Rh–O/N in the Ta3N5 shell layer. Rh-modifying significantly extended light absorption to the overall visible region. Localized built-in electric fields with hierarchical potential gradients at the multiple interfaces including a Rh/Ta3N5 Schottky junction and double n–n Ta3N5/TaON/Ta2O5 mutant heterojunctions, drove charge carriers to directionally transfer from inside to outside, and efficiently separate. Enhanced photoactivity was ascribed to a synergetic effect of improved light absorption ability, increased carrier separation efficiency, and accelerated surface reaction. A promising strategy of developing excellent Ta3N5-based photocatalysts for solar energy conversion is provided by constructing double n–n mutant heterojunctions.

Surface plasmon resonance excited electron induction greatly extends H2 evolution and pollutant degradation activity of g‐C3N4 under visible light irradiation

AbstractEnergy crises and environmental pollution have sparked tremendous research work to handle their impacts. Herein, we fabricated Au/g‐C3N4 nanocomposites to produce H2 and degrade 2,4‐dichlorophenol (2,4‐DCP) under visible light and at different wavelengths. Interestingly, the optimized photocatalyst generated 114 μmol H2 and degraded 25% 2,4‐DCP in 1 hr as compared with 10 μmol H2 generation and 8% 2,4‐DCP degradation by pure g‐C3N4. This improvement is credited to the extended light absorption and improved charge induction from gold to g‐C3N4 even at 590 nm as confirmed from photoluminescence, surface photovoltage, and photoelectrochemical study of the samples. Moreover, the surface catalytic property of g‐C3N4 was much improved after loading a proper amount of gold nanoparticles. We hope that this technique to photosensitize semiconductors with noble metal nanoparticles may provide a feasible way to construct surface plasmon resonance‐assisted photocatalysts to cope with energy crises and environmental pollution simultaneously.

Ni/Si-Codoped TiO2 Nanostructure Photoanode for Enhanced Photoelectrochemical Water Splitting.

We synthesized Ni/Si-codoped TiO2 nanostructures for photoelectrochemical (PEC) water splitting, by electrochemical anodization of Ti-1Ni-5Si alloy foils in ethylene glycol/glycerol solutions containing a small amount of water. The effects of annealing temperature on PEC properties of Ni/Si-codoped TiO2 photoanode were investigated. We found that the Ni/Si-codoped TiO2 photoanode annealed at 700 °C had an anatase-rutile mixed phase and exhibited the highest photocurrent density of 1.15 mA/cm2 at 0 V (vs. Ag/AgCl), corresponding to a photoconversion efficiency of 0.70%, which was superior to Ni-doped and Si-doped TiO2. This improvement in PEC water splitting could be attributed to the extended light absorption, faster charge transfer, possibly lower charge recombination, and longer lifetime.

Two-dimensional ultrathin BiOCl nanosheet/graphene heterojunction with enhanced photocatalytic activity

2D semiconductors and their heterostructures promise great potential in solar-driven photocatalysis owing to their unique properties that result from structural planar confinement. Herein, we fabricate the BiOCl nanosheet/graphene hybrid with 2D heterojunction through a hydrothermal and physical mixing two-step process. Studies on the heterostructure reveal the close interfacial contact between the BiOCl nanosheet and graphene through van der Waals interaction rather than chemical bonding. Compared with BiOCl-bulk/graphene hybrid, the BiOCl nanosheet/graphene hybrid showed superior photocatalytic activity towards dye decolorization and decomposition, featuring a remarkable enhancement of a 15-fold higher reaction rate. A series of characterizations reveal that the co-effect of the surface defect of the BiOCl nanosheet and graphene planar structure contributes to an extended light absorption range, better electrical conductivity and larger dye adsorption capacity. Furthermore, the unique van der Waals close contact between graphene and BiOCl promoted the fast and continuous consumption of photogenerated electrons, thereby effectively facilitating the separation of electron–hole pairs. This work underscores the key role of face-to-face heterojunction for the interfacial charge transfer process.

From One to Two: In Situ Construction of an Ultrathin 2D-2D Closely Bonded Heterojunction from a Single-Phase Monolayer Nanosheet.

Despite the many attempts to build ultrathin 2D-2D heterojunctions via wet chemical methods, the resulting composite materials reported to date suffer from poor interfacial bonding and/or complexity of the synthetic protocols. Encouraged by the structural compatibility of Bi2WO6 and Bi2O2S, both of which are 2D semiconductors sharing a rather similar structural unit of a [Bi2O2]2+ slice in their crystal structures, we have successfully fabricated an ultrathin nanosheet with a tightly bonded 2D-2D heterojunction between the two components by facilely joining the [Bi2O2]2+ and [S]2- slices using a simple two-step hydrothermal method. Such a Bi2WO6-Bi2O2S 2D-2D heterojunction has a five-alternating-layer (Bi2O2S-Bi2WO6-Bi2O2S-Bi2WO6-Bi2O2S) sandwich structure and a thickness down to ca. 5 nm and was obtained by simply growing the Bi2O2S layer in situ on the surface of monolayer Bi2WO6 nanosheets. The judicious combination of Bi2WO6 and Bi2O2S through a 2D-2D heterojunction not only extended light absorption in the visible range but also significantly enhanced photo(electro)chemical water splitting efficiencies in comparison to the bare Bi2WO6 nanosheets alone due to the close-bonding-promoted interfacial charge separation. Our findings provide a viable methodology to build a host of nanomaterials with closely bonded 2D nanosheets, which can be used as photocatalysts and electrocatalysts, among others.

Fabrication of porous TiO2-RGO hybrid aerogel for high-efficiency, visible-light photodegradation of dyes

In recent years, TiO2-graphene composites of various forms have attracted considerable attention as high-performance photocatalysts because of their desirable attributes including high adsorptivity of pollutants, extended light absorption range, and efficient charge separation. However, TiO2-graphene powders prepared via the classic hydrothermal method is faced with the obstacle of heavy agglomeration between graphene layers, which can cause a huge loss in adsorption and reaction sites. To improve this, we have employed graphene aerogel, which was synthesized via thermal reduction of graphene oxide (GO) aerogel, as an auxiliary material for TiO2. Herein, a highly porous TiO2-reduced graphene oxide (RGO) aerogel with high specific volume and enlarged specific surface area was presented, exhibiting considerably higher adsorption rate and capacity as well as improved photocatalytic efficiency, compared with classic hydrothermal-synthesized TiO2-graphene powders. The TiO2-RGO aerogels also showed high visible light absorption, endowing it with higher utilization of sunlight. This work presents a new approach for the synthesis of high-performance TiO2-graphene photocatalyst, and also provides a general graphene aerogel-based strategy for the improvement of various other photocatalysts.

Potassium-doped-C3N4/Cd0.5Zn0.5S photocatalysts toward the enhancement of photocatalytic activity under visible-light

The construction of new semiconductor photocatalysts toward the enhancement of photocatalytic activity under visible-light is crucial for a sustainable and clean future. In this paper, cation doping and heterojunction construction were synergistically used to synthesize g-C3N4 matrix composite with a narrow band gap and low recombination rate of photogenerated electron-hole pairs. Potassium-doped-C3N4 (KCN) was used as the matrix to construct semiconductor heterojunction with Cd0.5Zn0.5S (CZS) by hydrothermal method. The resulting composites were characterized through X-ray diffraction, infrared radiation, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, and ultraviolet–visible diffuse reflectance spectroscopy techniques to examine its phase structure, morphological, valance state and optical properties respectively. The photocatalytic performance of the samples evaluated by H2 evolution and degrading the Rhodamine B (RhB) aqueous solution. After 12 h hydrothermal reaction at 140 °C, CZS particles uniformly distributed on the KCN matrix. The photocatalytic hydrogen production rate (HPR) of the sample loaded 24 wt% CZS (KCN/CZS 24 wt%) reaches 1.83 mmol/g·h which is 5.6 times of pristine g-C3N4. The degradation rate constant on RhB of KCN/CZS 24 wt% is (k = 0.041 min−1) 7.9 times higher than g-C3N4. The enhanced photocatalytic activity can be attributed to the well-matched energy level of KCN and CZS as well as the extended light absorption of the composites.

Nitrogen doped carbon quantum dots and GO modified WO3 nanosheets combination as an effective visible photo catalyst

Nitrogen doped carbon quantum dots (NCQDs) based highly efficient ternary photocatalyst are fabricated by modifying surface of GO incorporated WO3 nano-sheets. XRD confirmed the formation of monoclinicWO3 nano-sheets. All the characteristic peaks of WO3, GO and NCQDs are obvious in XRD patterns of WO3/GO/NCQDs ternary photocatalysts confirming successful fabrication of the photocatalysts. SEM images showed that WO3 host matrix is distorted after incorporation of GO and NCQDs owing to lower interfacial tension. The surface of WO3 nano-sheets is modified with morphological defects making more active sites available. UV–vis spectra exhibited extended visible light absorption and remarkable reduction of WO3 band gap energy. The photoluminescence spectra confirmed the efficient charge separation in NCQDs modified ternary photocatalyst. The synthesized composites were applied for the photocatalytic degradation of harmful organic dye i.e. methyl orange (MO). The ternary composites represented the excellent photocatalytic activity as compared to binary and pure WO3 photocatalysts. This enhanced photocatalytic activity is attributed to the availability of active sites, extended light absorption in visible region and enhanced charge separation efficiency.

Multifunctional MoS 2 ultrathin nanoflakes loaded by Cd 0.5 Zn 0.5 S QDs for enhanced photocatalytic H 2 production

Two-dimensional MoS2 has been widely used as hydrogen evolution reaction (HER) cocatalyst to load onto nanostructured semiconductors for visible light-response photocatalytic hydrogen production. However, its another important role as light harvester because of the band-gap tunable property and beneficial band position has been rarely exploited. Herein, few layer-thick MoS2 nanoflakes with extended light absorption over the range of 400 to 680 nm and a photocatalytic HER rate of 0.98 mmol/h/g have been obtained. Then 7-nm-sized Cd0.5Zn0.5S quantum dots (QDs) are selectively grown upon ultrathin MoS2 nanoflakes for enhanced photocatalytic H2 generation. Upon the photocatalytic, light absorption, and charge transfer properties of the MoS2-Cd0.5Zn0.5S composites evolved with the amount of MoS2 from 0 to 3 wt%, the multiple roles of MoS2 as long-wavelength light absorber, in-plane carrier mediator, and edge site-active HER catalyst have been revealed. An optimum H2 generation rate of 8863 μmol/h/g and a solar to hydrogen (STH) efficiency of 2.15% have been achieved for 2 wt% MoS2-Cd0.5Zn0.5S flakes. Such a strategy can be applied to other cocatalysts with both the light response and HER activity for efficient photocatalytic property.

A novel CuInS2/m-BiVO4 p-n heterojunction photocatalyst with enhanced visible-light photocatalytic activity

Novel CuInS2/m-BiVO4 composites with different mass ratios (CuInS2 to m-BiVO4 = 1:3, 1:1, and 3:1) were synthesized and their potential visible-light photocatalytic applications for photodegradation of some organic dyes (methylene blue, rhodamine B, and methyl orange) and inactivation of bacteria (Pseudomonas aeruginosa) were investigated. CuInS2/m-BiVO4 with a mass ratio of 1:3 exhibited better photocatalytic degradation of methylene blue and antibacterial activity than those of either pure CuInS2 or m-BiVO4. Moreover, this composite photocatalyst showed different photocatalytic selectivity in terms of the organic dye degradation. Salicylic acid was also used to test the photocatalytic activity of this composite to clarify the dye sensitization effect. The photoelectrochemical (PEC) properties of the CuInS2/m-BiVO4 photoelectrode, evaluated by linear sweep voltammetry (LSV) measurement, revealed that the composite photoelectrode exhibited higher current density and onset potential in comparison with the m-BiVO4 photoelectrode. In addition, the electrochemical impedance spectroscopy (EIS) measurement also proved a faster rate of charge transfer at the electrode/electrolyte interface. The enhancement of photocatalytic and PEC activities of the CuInS2/m-BiVO4 composite was revealed not only that the CuInS2/m-BiVO4 composite extended light absorption in the visible light region, but also that the formation of a p-n heterojunction could promote photogenerated charges as well as facilitate effective charge separation and transportation between the CuInS2 and m-BiVO4 contact interface.

Toward efficient photocatalytic pure water splitting for simultaneous H2 and H2O2 production

Although overall water splitting with particulate photocatalysts is considered as an ideal means towards solar-to-hydrogen conversion, practical application of the promising technique is greatly inhibited by the congenital defects including H2/O2 separation and unfavorable four-electron kinetics. In this context, photocatalytic overall water splitting for simultaneous H2 and H2O2 generation via a two-electron pathway can readily address these issues. Here, we report a novel CoxNiyP cluster incorporated P-doped g-C3N4 photocatalyst (CoxNiyP-PCN) by a two-step phosphating method that presents such unique behavior for pure water splitting into stoichiometric H2 and H2O2. The highest H2 evolution rate reaches 239.3 μmol h−1 g−1, achieved over the CoNiP–PCN photocatalyst, which is among the best reported activities for overall water splitting. It is found that both P and the cluster cocatalyst are critical to the remarkably improved photocatalytic activity. Specifically, P as a substitution of C in PCN introduces a positive charge center (P+), reinforcing the chemical connection between PCN and CoNiP, in a form of P+-Pδ--Coδ+/Niδ+. This unique bridging effect, together with the extended light absorption by P doping and optimized surface redox potential by cocatalyst integration, stimulates efficient vectorial charge transfer between PCN and CoNiP and subsequent surface mass exchange. On the other hand, we also demonstrate that the well satisfied band structure of PCN can facilitate the two-electron reaction pathway. This work not only has implications for the potential use of CoNiP–PCN as potential photocatalyst for solar H2 production, but also offers a new idea for pure water slitting in particulate system.

Dual Cocatalysts in TiO2 Photocatalysis.

Semiconductor photocatalysis is recognized as a promising strategy to simultaneously address energy needs and environmental pollution. Titanium dioxide (TiO2 ) has been investigated for such applications due to its low cost, nontoxicity, and high chemical stability. However, pristine TiO2 still suffers from low utilization of visible light and high photogenerated-charge-carrier recombination rate. Recently, TiO2 photocatalysts modified by dual cocatalysts with different functions have attracted much attention due to the extended light absorption, enhanced reactant adsorption, and promoted charge-carrier-separation efficiency granted by various cocatalysts. Recent progress on the component and structural design of dual cocatalysts in TiO2 photocatalysts is summarized. Depending on their components, dual cocatalysts decorated on TiO2 photocatalysts can be divided into the following categories: bimetallic cocatalysts, metal-metal oxide/sulfide cocatalysts, metal-graphene cocatalysts, and metal oxide/sulfide-graphene cocatalysts. Depending on their architecture, they can be categorized into randomly deposited binary cocatalysts, facet-dependent selective-deposition binary cocatalysts, and core-shell structural binary cocatalysts. Concluding perspectives on the challenges and opportunities for the further exploration of dual cocatalyst-modified TiO2 photocatalysts are presented.

A free-standing 3D nano-composite photo-electrode—Ag/ZnO nanorods arrays on Ni foam effectively degrade berberine

Berberine is a widely used antibiotic in China, its photocatalytic degradation is not well understood nor its efficient treatment reported. In this study, it is most quickly and efficiently degraded (97.9% under UV and 98.9% under visible light) using a free-standing 3D composite photo-electrode, with well dispersed Ag nanoparticles (Ag NPs) over well-aligned ZnO nanorods arrays (ZnO NAs) on Ni foam (NiF), compared to ZnO NAs/NiF, ZnO powder and P25. The composite photo-electrode was prepared by first directly growing ZnO NAs on NiF hydrothermally, followed by photo-deposition of Ag NPs, without any inactive binders or non-conductive substrates. It was characterized using scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), X-ray Diffraction (XRD), ultraviolet–visible spectrophotometry (UV–Vis) and electrochemical analysis (I-t, EIS). The highest activity of Ag NPs/ZnO NAs/NiF in degrading the target pollutant, is due to the synergy of easy pollutants diffusion and fast reaction on active sites, from suppressed electron-hole recombination by Ag NPs/ZnO NAs heterojunctions, extended light absorption by surface plasmon resonance (SPR) of Ag NPs and accelerated electron transport on the conductive macro-porous NiF. The reactive oxidizing species (OH, O2−, h±), degradation intermediates and possible degradation pathways of berberine over Ag NPs/ZnO NAs/NiF were examined respectively. This free-standing whole piece photo-electrode with UV–visible light response, is easy to recycle and assemble, that not only degrades pollutant, but also generates electricity as photo-anode in a photo-catalytic fuel cell reactor using carbon fiber cloth as cathode.

In-situ solid phase thermal transformation of self-assembled melamine phosphotungstates produce efficient visible light photocatalysts

Visible-light-driven stacked-layer heterogeneous photocatalyst carbonitride/tungstophosphate (TCN) was constructed via in-situ solid-state thermal transformation using melamine phosphotungstate (MPW). The structural, morphological and optical properties of the samples were investigated. Compared to the MPW hybrids and phosphotungstic acid hydrate, the TCN photocatalysts showed excellent visible light photocatalytic activity. During the thermal transformation, the melamine molecules polymerize to form the defective heptazine structure carbonitride attached to the surface of mixed-valence Keggin units. The interfacial POMs anions-π interactions, ligand-to-metal charge transfer and mix-valence organic-POMs structure makes the electrons fully delocalized over the MPW hybrids, and the TCN photocatalysts obtain the extended light absorption. The Keggin units accept and transfer electrons, so the recombination of photogenerated carriers is suppressed. 13TCN-390 obtains the optimal photocatalytic activity, its photocatalytic degradation efficiency of imidacloprid and rate constant k are 6.38 and 13.50 times than that of CN-390, respectively. The enhanced photocatalytic activity arises from the extended light absorption, suppressed photogenerated carriers’ recombination, surface structure defect and suitable band structure. h+ and OH are the main reactive species when the proposed photocatalytic mechanism was done. This study provides a promising construction strategy for polymer/POMs photocatalysts using different organic-POMs hybrids.

Efficient Degradation of Gas-Phase Toluene by Ozone-Assisted Photocatalytic Oxidation on TiO2/Graphene Composites

Ozone-assisted photocatalytic oxidation was employed for the degradation of gas-phase toluene in this study. TiO2/graphene (GR) composites with different addition ratios (0.1, 0.5, 1 and 2 wt%) of graphene were synthesized. XRD, SEM (with EDS), TEM, BET, UV–vis DRS, PL and photochemical measurements were conducted to investigate the physical, optical and photochemical properties. The results indicated that TiO2 nanoparticles were smoothly loaded on the graphene nanosheets, and the as-synthesized TiO2/GR composites possessed excellent properties such as extended light absorption range, efficient charge separation and transfer ability, and broadened lifetimes of photo-generated carriers. The effect of water vapor in the ozone-assisted photocatalytic oxidation reactions was also studied, which was found to be essential for the degradation of toluene. When the relative humidity was 80%, TiO2/GR (0.1 wt%) exhibited the highest toluene removal efficiency of 97.2% among all the samples, and other TiO2/GR composites also exhibited better toluene degradation performance than bare TiO2. Furthermore, the introduction of ozone was helpful for the improvement of photocatalytic performance. The promotion mechanism was proposed that the addition of an appropriate amount of graphene in TiO2 was helpful for the separation and transfer of photo-excited carriers, thereby reducing the recombination of e−/h+ pairs and promoting the formation of oxidizing species such as oxygen negative radicals (O3−·, O−·) and hydroxyl radicals (OH·). Overall, this work could provide a new insight into the fabrication of TiO2/GR composites as high performance photocatalysts in the environmental protection issues.

Visible light photocatalytic performance of laser-modified TiO2/SnO2 powders decorated with SiC nanocrystals

Abstract In this work, silicon carbide nanocrystals (SiC NCs) were prepared via ultrasonic vibration treatment on the electrochemical etched SiC target. TiO2/SnO2 powders were pulsed-laser ablated in deionized water with different duration. Then, the SiC NCs were coupled with the laser modified powders, forming the SiC-TiO2/SnO2 nanocomposites. As-prepared nanocomposites exhibit extended light absorption to the visible range. The abilities for photocatalytic degradation of the heterostructured catalysts were greatly enhanced in comparison with the pristine and the ablated TiO2/SnO2 powders. It was ascribed to the heterojunction structure between SiC NCs and TiO2/SnO2, which reduces the recombination of photogenerated electrons and holes.

Boosting electron population in δ-Bi2O3 through iron doping for improved photocatalytic activity

We successfully stabilize the delta phase of bismuth oxide (δ-Bi2O3) down to room temperature through a simple hydrothermal method. The prepared δ-Bi2O3, which is composed of ultrathin nanosheets, possesses excellent crystallinity. When δ-Bi2O3 is doped with Fe3+, the photocatalytic activity for the mineralization of a number of refractory organic compounds is improved. The improved photocatalytic activity is caused by an increased electron population upon the Fe3+ doping. Additional thermal treatment through a post-calcination at 500 °C under air atmosphere results in further increases of photocatalytic activity due to the improved crystallinity, extended light absorption, and better incorporation of Fe3+ into the host lattice.

Shell thickness dependent photocatalytic activity of EDTA-assisted Ag/ZnO core-shell nanoparticles under sunlight irradiation

Functionalized Ag/ZnO core–shell (CS) nanoparticles (NPs) with ethylenediaminetetraacetic acid (EDTA) having same core size but with different shell thickness are successfully prepared through a simple and low cost wet chemical process. Different physiochemical characterizations including transmission electron microscopy, x-ray diffraction, Brunauer-Emment-Teller surface area analysis, zeta potential analysis, thermal gravimetric-differential analysis, UV-visible absorption spectroscopy, Photoluminescence Spectroscopy and Fourier-transform infrared Spectroscopy have been involved to characterize the samples. The thickness of ZnO shell of Ag/ZnO CS NPs is found to be increasing with increasing molar ratio of EDTA/Zn2+. The LSPR wavelength of Ag core is shifting to longer visible wavelength with increasing the shell thickness of Ag/ZnO CS NPs because of the increase in the dielectric constant of the sourrounding environment. The increasing shell thickness of Ag/ZnO CS NPs makes a strong effect on the decrease in the fluorescence intensity of UV emission of ZnO. This quenching of PL intensity has been further verified by transient fluorescence (FL) spectra. The Nyquist plots also provide evidence of higher electron-transfer rate of the Ag/ZnO CS NPs of having higher shell thickness. The photocurrent measurement confirms electron-charging of Ag core in Ag/ZnO CS NPs. Variation of concentration of EDTA as anionic surfactant causes variation of surface charge of Ag/ZnO CS NPs. With increasing the shell thickness, photodegradation efficiency of Ag/ZnO CS NPs towards methylene blue (MB) degradation enhances under sunlight irradiation. This enhancement in photocatalytic efficiency with increasing the shell thickness is achieved due to the higher surface area, higher charge transfer efficiency, extended light absorption towards visible region and more negative zeta potential of Ag/ZnO CS NPs.

Hand-in-hand quantum dot assembly sensitized photocathodes for enhanced photoelectrochemical hydrogen evolution

A hand-in-hand QD assembly sensitized photocathode with extended light absorption and oriented charge transfer is established for enhanced PEC water splitting, which is comparable to or even better than those external cocatalyst-assisted systems.

Effect of Reduced Grapheme Oxide in Enhancing the Photocatalytic Activity of β-NaYF<sub>4</sub>:Ho<sup>3+</sup>@TiO<sub>2</sub>

β-NaYF₄:Ho³⁺@TiO₂–reduced graphene oxide (NYFH@TO–rGO) ternary composites photocatalysts were prepared via a three-step method and used for cleanup of Rhodamine B (RhB) aqueous solution under visible light irradiation. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), fluorescence spectrometries, ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), electron spin resonance (ESR), and photoelectrochemical properties were used to characterize the photocatalyst. The results revealed that rGO as an excellent platform and successfully to load NYFHo@TO core–shell microcrystals. In this photocatalyst, the loading of UC microcrystals is expected to emit UV (290 nm) light after absorbing Vis (450 nm) light of the solar spectrum and the optical response of the rGO is enhanced from UV to Vis. so as to realize the visible light-driven photocatalysis of TiO₂. It was found that add to rGO can efficient charge separation, extended light absorption range (red-shifted to 402.6 nm), enhanced adsorption performance, and improve photocatalytic activity. This novel tenary photocatalyst can reach decomposition rate of RhB as high as 87% after 10 h of irradiation by visible-light Xe lamp. Compared with the blank experiment, the efficiency was significantly improved. It is of great significance to design an effective solar light-driven photocatalysis in promoting environmental protection.