Simulated Sunlight Irradiation Research Articles

Na-mediated carbon nitride realizing CO2 photoreduction with selectivity modulation

The depressed directional separation of photogenerated carriers and weak CO2 adsorption/activation activity are the main factors hampering the development of artificial photosynthesis. Herein, Na ions are embedded in graphitic carbon nitride (g-C3N4) to achieve directional migration of the photo-generated electrons to Na sites, while the electron-rich Na sites enhance CO2 adsorption and activation. Na/g-C3N4 (NaCN) shows improved photocatalytic reduction activity of CO2 to CO and CH4, and under simulated sunlight irradiation, the CO yield of NaCN synthesized by embedding Na at 550 ℃ (NaCN-550) is 371.2 μmol g−1h−1, which is 58.9 times bigger than that of the monomer g-C3N4. By means of theoretical calculations and experiments including in situ FTIR, the mechanism is investigated. This strategy which improves carrier separation and reduces the energy barrier at the same time is important to the development of artificial photosynthesis.

Novel high entropy alloy/NiAl2O4 photocatalysts for the degradation of tetracycline hydrochloride: Heterojunction construction, performance evaluation and mechanistic insights

Novel NiAl2O4 (NAO)/high entropy alloy (HEA) (Ti), NAO/HEA (Mn) and NAO/HEA (Mo) heterojunction photocatalysts with high photocatalytic activity for the degradation of tetracycline hydrochloride (TC) under simulated sunlight irradiation were synthesized by the polyacrylamide gel method combined with a low temperature sintering technique. The effects of environmental parameters, including drug concentration, catalyst content and pH value, on the photocatalytic activity of NAO/HEA photocatalysts were investigated in detail on the basis of the response surface methodology (RSM) and experimental results. The optimal initial TC concentration, catalyst content, and pH were 100 mg/L, 1 g/L, and 5, respectively. The photocatalytic activity of NAO/HEA photocatalyst (84.6 %) was significantly improved compared to the degradation percentage of HEA (Ti) photocatalyst (36.5 %). The roles of active free radicals including h+, •O2−, •OH and oxygen vacancy in photocatalysis were verified using multiple characterization methods. In-depth analysis was conducted on the degradation pathway of TC, the safety of degradation intermediates, and the photocatalytic mechanism of NAO/HEA (Ti) photocatalyst. The Z - scheme heterojunction can significantly improve the transport efficiency of photogenerated carriers and inhibit the recombination rate of electron hole pairs in the system, which provides a new idea for exploring the application of new HEA - based heterojunction photocatalysts in the field of photocatalysis.

Insights into sunlight-driven transformation of tetracycline by iron (hydr)oxides: The dominating role of self-generated hydrogen peroxide

Iron (hydr)oxides are abundant in surface environment, and actively participate in the transformation of organic pollutants due to their large specific surface areas and redox activity. This work investigated the transformation of tetracycline (TC) in the presence of three common iron (hydr)oxides, hematite (Hem), goethite (Goe), and ferrihydrite (Fh), under simulated sunlight irradiation. These iron (hydr)oxides exhibited photoactivity and facilitated the transformation of TC with the initial phototransformation rates decreased in the order of: Hem > Fh > Goe. The linear correlation between TC removal efficiency and the yield of HO• suggests that HO• dominated TC transformation. The HO• was produced by UV-induced decomposition of self-generated H2O2 and surface Fe2+-triggered photo-Fenton reaction. The experimental results indicate that the generation of HO• was controlled by H2O2, while surface Fe2+ was in excess. Sunlight-driven H2O2 production in the presence of the highly crystalline Hem and Goe occurred through a one-step two-electron reduction pathway, while the process was contributed by both O2-induced Fe2+ oxidation and direct reduction of O2 by electrons on the conduction band in the presence of the poorly crystalline Fh. These findings demonstrate that sunlight may significantly accelerate the degradation of organic pollutants in the presence of iron (hydr)oxides.

Preparation of Bi4Ti3O12/TiO2 by flame spray pyrolysis for photoelectrocatalytic degradation of tetracycline

The negative effects of the irrational use of antibiotics have been increasing attention from the public, making it urgently needed to develop effective techniques for removing antibiotics from wastewater. Simultaneously, the construction of heterogeneous TiO2 photoanodes can be used to enhance photoelectrocatalytic performance. Herein, we used an advanced method, namely one-step flame spray pyrolysis (FSP) to in-situ prepare Bi4Ti3O12/TiO2 heterostructures. The ultra-high temperature characteristics of this method facilitated the high dispersion of Bi species on TiO2, leading to the formation of the Bi4Ti3O12 phase within milliseconds. Bi4Ti3O12 forms a "Z" type heterojunction with TiO2, improving charge separation and enhancing electron transfer efficiency. The photoeletrocatalytic degradation effect of Bi4Ti3O12/TiO2 on tetracycline is significantly improved. Under simulated sunlight irradiation for 75 min and 1V voltage, the removal of tetracycline can reach 99.7%. The recycling degradation experiments demonstrated the remarkable reusability and stability of Bi4Ti3O12/TiO2, while the evaluation of degradation intermediates and toxicity analysis of tetracycline were also conducted. Furthermore, free radical trapping experiments confirmed that hydroxyl radicals and holes play a significant role in the removal of tetracycline.

Synergistically electronic interacted PVDF/CdS/TiO2 organic-inorganic photocatalytic membrane for multi-field driven panel wastewater purification

Solar-driven wastewater purification technology is a promising candidate to solve the hazards of water contaminants. However, it is difficult for most of particulate photocatalysts to maintain durable photoactivity due to its micro/nano size. Herein, a synergistically electronic interacted membrane catalyst with large extending area and high pollutant capture capacity was processed based on a highly active CdS/TiO2 heterojunction and ferroelectric polyvinylidene fluoride for achieving highly efficient Cr6+-to-Cr3+ (CTC) reduction (1.6×10−2 min−1) and synchronous decomposition of organic matters (methylene blue (1.2×10−2 min−1) and bisphenol A (0.6×10−2 min−1)) under simulated sunlight (SSL, 74.1 mW·cm−2) irradiation following a durably steady photoactivity even being recycled for 20 times, which effectively avoided the hazards of secondary pollution. Subsequently, a tailor-made panel wastewater purification system was first built based on this membrane catalyst to drive CTC reduction and synchronous organic matter degradation, and high-efficiency purification performance was presented on this panel system under multi-field drive of light-activation and piezoelectric polarization. This work provides an insight for photocatalytic wastewater purification through membrane catalyst assisted panel technology.

Photonic enhanced flexible photothermoelectric generator using MXene coated fullerenes modified PEDOT:PSS films for solar energy harvesting

Photothermoelectric conversion technology from light and heat into electricity has been proved to be an effective method and associated with photothermal and thermoelectric (TE) effects. Wherein, there are great challenges in the structural design that the cold and hot side distribution in planar structure limits the selection of materials to obtain the high output voltage. Here, the half-vertical heterojunction structure of the photothermoelectric generator (PTEG) is adopted for enhanced performance to realize effective energy utilization. The PTEG is constituted by the MXene half-coated fullerenes-modified PEDOT:PSS to obtain wide spectral response. The output voltage of the prepared PTEG can be stabilized at 2.15 mV under the irradiation of a laser wavelength 808 nm with power of 25 mW. Under simulated sunlight irradiation, with the assistant of fullerenes, the output voltage was improved by 43.83 % from 146 to 210μ V. Furthermore, the voltage can be enhanced by TE voltage increasement via temperature gradient, and the 66.19 % increment of output voltage is evaluated from 210 to 349 μV. In addition, PTEG has also excellent electrothermal effect, which was applied into detecting whether the battery is fully charged via adhering to thermal sensitive materials. By means of half-vertical heterojunction structure to the PTEG, a new choice for the PTEG is provided to make better use of sunlight.

Construction of Bi2O3−x/NiAl-LDH S-scheme heterojunction for boosting photothermal-assisted photocatalytic CO2 reduction

In this study, a new type of 2D/2D Bi2O3−x/NiAl-LDH (BO/NA-LDH) S-scheme photocatalyst was prepared by combining NiAl-LDH with Bi2O3−x by wet chemical deposition for obtaining efficient photothermal-assisted photocatalytic reduction of CO2 under simulated sunlight irradiation. In particular, the as-prepared optimal 50-BO/NA-LDH sample exhibited the CO production yield of 83.55 ± 2.76 μmol/g/h, which was 9 and 27 times that of BO (9.32 ± 0.62 μmol/g/h) and NA-LDH (3.09 ± 0.38 μmol/g/h), respectively. The enhancement of photothermal-assisted activity over the 50-BO/NA-LDH system was mainly attributed to the coupling of the photothermal conversion performance of Bi2O3−x and improving the migration efficiency of interface carriers of S-scheme heterojunction and 2D/2D structure. This study presents a promising strategy for the development of high-efficient photothermal-assisted photocatalysts.

Optimizing Conductive Polymer Bulk Structure: Influence of Polymerization Temperature on Photocatalytic Performance for Sustainable Hydrogen Production

The influence of the polymerization temperature upon the bulk‐structure‐doped conductive polymer polyaniline (emeraldine‐salt, PANI) on the semiconducting, optical, and electrical properties of the photocatalyst is investigated. When the B‐PANI polymerization temperature increases from 5 to 60 °C, the crystallinity and conductivity of Pt/N‐TiO2/B‐PANI (PNT/B‐PANI) decreases. To rectify the problems of recycling convenience and secondary pollution, this study combines a photocatalyst and a porous polystyrene film for sustainable hydrogen production. The photocatalytic performance of the polystyrene/PNT/B‐PANI‐5 (PS/PNT/B‐PANI‐5) photocatalyst film (27 047 μmol h−1 g−1) under simulated sunlight irradiation is enhanced by a factor of up to 1.6 compared to that of PS/PNT. Therefore, the PS/PNT/B‐PANI photocatalyst film is a visible‐light photocatalyst which is a promising candidate for enhancing photocatalytic recycling convenience.

TiO2 nanotubes immobilized on polyurethane foam as a floating photocatalyst for water treatment

We investigated the photocatalytic activity of TiO2 nanoparticles (TiO2-NPs) and TiO2 nanotubes (TiO2-NTs) supported on a floating polyurethane (PU) foam for removing Bisphenol A (BPA) as a model pollutant. We fabricated TiO2-NPs by the sol-gel method and TiO2-NTs by the ultrasound-assisted hydrothermal method. Subsequently, the photocatalysts were immobilized onto the PU foam through the wet chemical deposition process. The synthesized photocatalysts were characterized by contact angle, SEM-EDS, TEM, XRD, DRS, and BET analyses. TiO2-NPs and TiO2-NTs were successfully deposited onto the PU foam, creating floating photocatalysts denoted as TiO2-NPs@PU and TiO2-NTs@PU. Our findings indicated that the nanotubular structure of floating TiO2 photocatalysts enhanced the removal efficiency of BPA relative to the nanoparticles, resulting in the complete removal of the pollutant over 180 min of simulated sunlight irradiation. TiO2-NTs@PU was also stable after five reuse cycles. Moreover, h+ was the main scavenging reactive species during the photocatalysis of BPA with TiO2-NTs@PU.

Solar Gas-Phase CO2 Hydrogenation by Multifunctional UiO-66 Photocatalysts.

Solar-assisted CO2 conversion into fuels and chemical products involves a range of technologies aimed at driving industrial decarbonization methods. In this work, we report on the development of a series of multifunctional metal-organic frameworks (MOFs) based on nitro- or amino-functionalized UiO-66(M) (M: Zr or Zr/Ti) supported RuOx NPs as photocatalysts, having different energy band level diagrams, for CO2 hydrogenation under simulated concentrated sunlight irradiation. RuOx(1 wt %; 2.2 ± 0.9 nm)@UiO-66(Zr/Ti)-NO2 was found to be a reusable photocatalyst, to be selective for CO2 methanation (5.03 mmol g-1 after 22 h;, apparent quantum yield at 350, 400, and 600 nm of 1.67, 0.25, and 0.01%, respectively), and to show about 3-6 times activity compared with previous investigations. The photocatalysts were characterized by advanced spectroscopic techniques like femto- and nanosecond transient absorption, spin electron resonance, and photoluminescence spectroscopies together with (photo)electrochemical measurements. The photocatalytic CO2 methanation mechanism was assessed by operando FTIR spectroscopy. The results indicate that the most active photocatalyst operates under a dual photochemical and photothermal mechanism. This investigation shows the potential of multifunctional MOFs as photocatalysts for solar-driven CO2 recycling.

Lotus pollen-derived nitrogen and phosphorus self-doped TiO2/carbon materials for photoelectrochemical application

The wide band gap and low conductivity of TiO2 limit its application for photocatalytic H2 production. In this work, a nitrogen (N) and phosphorus (P) self-doped TiO2/Carbon (TiO2/C) composite with an egg yolk-shell structure was successfully synthesized using a lotus pollen template synthesis approach. The microstructure and photoelectrochemical performance of the composite materials were investigated. The introduction of hetero elements decreased the band gap of the TiO2/C composite, extending light absorption to the visible light region. Additionally, the enhanced conductivity facilitated fast charge transfer and prolonged the lifespan of electron/hole pairs. Consequently, the N, P self-doped TiO2/C composite exhibited higher H2 production (656.18 μmol·g−1·h−1) than commercial TiO2 (418.12 μmol·g−1·h−1) under simulated sunlight irradiation.

Photocatalytic Activity and Antibacterial Properties of ZnO/CNTs Composites

Photocatalytic technology is one of the promising technologies for wastewater treatment. Herein, zinc oxide/multi-walled carbon nanotubes (ZnO/CNTs) photocatalyst was successfully prepared by hydrothermal method with combining in-situ synthesis technology. The micro-morphology, crystalline structure, surface chemical elements, and optical properties were characterized by SEM, TEM, XRD, FTIR, UV-Vis, and DRS technologies. The ZnO/CNTs photo-catalyst exhibited enhancement photo activity for degradation of organic pollutants under simulated light irradiation. Specifically, the photo-catalytic activity of the ZnO/CNTs catalysts improved with the rise of CNTs content in the composites. Investigation on the photo-degradation mechanism verified that the presence of CNTs in the catalyst not only optimized the band structure of ZnO semiconductor but also contributed to the transfer of photo-generated electrons and reducing the recombination of electron-hole pairs due to its excellent conductivity. Moreover, the active radical groups such as superoxide radical (O-2), hole (h+), and hydroxyl radical (·OH) played the dominated role for the pollutants degradation under the simulated sunlight irradiation. In addition, ZCT20 catalysts and light irradiation had synergistic effects on antibacterial activity, whose antibacterial rates against E. coli and S. aureus were up to 99.96% and 99.94%, respectively. Investigation on antibacterial mechanisms revealed that the existence of ROS and the continuous release of Zn2+ played an important role for improving the antibacterial activity of the ZCT20 catalyst under the simulated sunlight irradiation.

Photochemical fate of β-blocker pindolol in riverine and its downstream coastal waters

Pindolol (PIN) is a commonly used β-blocker drug and has been frequently detected in various natural waters. Comprehensive understanding of its environmental photochemical transformation is necessary to assess its environmental risk. In this study, the photodegradation kinetics and mechanisms of PIN in both freshwater and coastal water were investigated for the first time. The photodegradation experiments were carried out by steady-state photochemical experiment under simulated sunlight irradiation. The results showed that the photodegradation rate of PIN in the freshwater of the Pearl River estuary was significantly faster than that in its downstream coastal water. In river water, PIN can undergo both direct photolysis and indirect photolysis induced by riverine dissolved organic matter (DOM) mainly through excited triplet-state of DOM and singlet oxygen, while direct photolysis dominated its degradation in coastal water. The promotion effect was found to be much greater for Suwannee River Natural Organic Matter (SRNOM) than that of the sampled riverine DOM, due to its high steady-state concentrations of reactive species. Interestingly, coastal DOM in northern and southern China were found to have similar promotion effects on PIN photodegradation for the first time, but both less than that of riverine DOM. A total of seven degradation products of PIN resulting from hydroxylation, hydrogen abstraction and cleavage of ether bond were identified. Biological toxicity of one products were found to be higher than that of PIN. These results are of significance for knowing the persistence and ecological risk of PIN in natural waters.

Enhanced photocatalytic CO2 reduction via single-atom Au anchored on ZnIn2S4 nanosheets

In this study, we systematically investigated the effect of single-atom gold (Au) loaded on ZnIn2S4 nanosheets on the photocatalytic reduction of carbon dioxide (CO2). Utilizing a photodeposition method, we successfully dispersed single-atom Au uniformly on the surface of ZnIn2S4 nanosheets. Under simulated sunlight irradiation, the Au-loaded catalyst demonstrated a higher yield and selectivity in the CO2 reduction reaction compared to the pure ZnIn2S4 nanosheets. Surface photovoltage testing revealed that the addition of Au significantly enhanced the separation efficiency of photo-generated charge carriers, thereby improving the photocatalytic efficiency. Density functional theory calculations indicated that the loading of single-atom Au reduced the reaction energy barrier from CO2 to CO, enhancing the selectivity of photocatalytic CO2 reduction. This research not only developed an efficient catalyst for CO2 reduction but also provided deep insights into the mechanism of single-atom catalysts in the photocatalytic CO2 reduction process through extensive experimental and theoretical analysis.

Eight-Electron Copper Nanoclusters for Photothermal Conversion.

Owing to distinct physicochemical properties in comparison to gold and silver counterparts, atomically precise copper nanoclusters are attracting embryonic interest in material science. The introduction of copper cluster nanomaterials in more interesting fields is currently urgent and desired. Reported in this work are novel copper nanoclusters of [XCu54Cl12(tBuS)20(NO3)12] (X=S or none, tBuSH=2-methyl-2-propanethiol), which exhibit high performance in photothermal conversion. The clusters have been prepared in one pot and characterized by combinatorial techniques including ultraviolet-visible spectroscopy (UV-vis), electrospray ionization mass spectrometry (ESI-MS), and X-ray photoelectron spectroscopy (XPS). The molecular structure of the clusters, as revealed by single crystal X-ray diffraction analysis (SCXRD), shows the concentric three-shell Russian doll arrangement of X@Cu14@Cl12@Cu40. Interestingly, the [SCu54Cl12(tBuS)20(NO3)12] cluster contains 8 free valence electrons in its structure, making it the first eight-electron copper nanocluster stabilized by thiolates. More impressively, the clusters possess an effective photothermal conversion (temperature increases by 71 °C within ~50 s, λex=445 nm, 0.5 W cm-2) in a wide wavelength range (either blue or near-infrared). The photothermal conversion can be even driven under irradiation of simulated sunlight (3 sun), endowing the clusters with great potency in solar energy utilization.

Intensified photo-decontamination of tetracycline antibiotic by S-scheme spinel manganese ferrite-grafted ZIF-8 heterojunction photocatalyst: Mechanism conception, degradation pathway and DFT studies

The enhancing outbreaks of refractory pharmaceutical compounds in aquatic bodies and subsequent adverse influences on the ecosystem have resulted in great environmental aggravation for living creatures throughout the world. In response to this issue, constructing a step-scheme (S-scheme) for pharmaceuticals elimination is of great importance. In this contribution, a robust MnFe2O4/ZIF-8 S-scheme heterojunction was constructed via an environmentally benign green approach. The physicochemical properties of the MnFe2O4/ZIF-8 heterojunction were verified utilizing multiple characterization techniques. The as-designed MnFe2O4/ZIF-8 nanomaterial was applied as a photocatalyst for decontaminating tetracycline (TC) by irradiation with simulated sunlight. The purification experiments demonstrated that the complete removal of TC was achieved at the pH of 9.0, catalyst quantity of 0.5g/L, and TC dosage of 5mg/L in the presence of simulated sunlight for 200min. Besides, HO• radicals were inferred to be the primary oxidizing agents in the photo-decontamination of TC by MnFe2O4/ZIF-8 and exhibited unique photocatalytic reactivity for TC after the six-succeeding recycle experiment. EIS, Mott-Schottky, radical capture experiment, and transient photo-current were used to elucidate the probable photocatalytic degradation mechanism of the S-scheme systematically. Furthermore, the possible decontamination pathways of TC were deduced through intermediate analysis and density functional theory (DFT) computations. Concomitantly, the biodegradation ability of the MnFe2O4/ZIF-8/xenon system was evaluated from pharmaceutical wastewater purification. These experiments showed that the AOS and COS levels of the wastewater sample elevated from 1.7 to 2.4 and 3.1, respectively, under simulated sunlight irradiation, manifesting the robust oxidation of stubborn organic substances by employing the investigated system.

Photoproduction of Hydroxyl Radicals Under Sunlight by Fe-Zn Oxides for Partial Oxidation Applications

Iron-zinc oxide (FZ) photocatalysts with activity in the visible region were designed for the partial oxidation of organic molecules with the least loss of raw material. The FZ materials were synthesized using the sol-gel method with citric acid as a stabilizing agent. From TGA results, 400 °C was observed as the minimum temperature for precursors degradation, then two thermal treatment times were assessed at 60 and 180 min. The powder photocatalysts were comprehensively characterized by TGA, DSC, FTIR, XRD, Raman, Mössbauer, XPS, UV-Vis, and SEM. The production of hydroxyl radicals (•OH) was followed by the fluorescence emission of 2-hydroxy-terephthalic acid (OHTA). The absorbance decrease of methylene blue (MB) and disodium terephthalate (NaTA) was measured by UV-Vis spectroscopy to calculate the total degradation degree. The photocatalytic activity of FZ materials was quantified after 2 h under simulated sunlight radiation at room temperature conditions. All FZ oxides treated for 60 min presented no •OH detection, in which photocatalytic blanks showed an adsorption phenomenon of the probe molecules. FZ7 and FZ8 materials showed the best •OH production and the least MB/NaTA degradation, making them the best candidates for partial oxidation applications.

Adjustable n→π* electronic transition by sulfonated benzene functionalized g-C3N4 for enhanced photocatalytic H2 generation

The photocatalytic efficiency of graphitic carbon nitride (g-C3N4) in hydrogen production is primarily hindered by its poor absorption of visible light, rapid recombination of electron-hole pairs, and the absence of hydroxyl radical formation. Herein, a novel g-C3N4 nanosheets functionalized with sulfonic acid groups were effectively produced through thermal polymerization of melamine and 2, 4-diamino-6-phenyl-1, 3, 5-triazine (DPT), followed by sulfonation treatment. The introduction of the phenyl group brings about alterations to the initial symmetrical arrangement of g-C3N4, leading to the disruption of certain hydrogen bonds. This, in turn, facilitates the movement of electrons from the n to π* orbitals, resulting in enhanced light absorption and improved efficiency in charge separation. Moreover, it induces modifications to the band structure and amplifies the production of hydroxyl radicals. Additionally, the introduction of sulfonic acid enhances the water affinity and the ability of dispersing graphitic carbon nitride in water. The optimized sulfonated benzene-substituted g-C3N4 (1000-BCN-SO3H) with a melamine to DPT ratio of 4:1 exhibits a maximum hydrogen production rate of 6.52 mmol·h−1·g−1 under simulated sunlight irradiation with good cycling stability, which is 3.93 times higher than that of g-C3N4 nanosheets. This research offers a promising opportunity for a novel approach in advancing carbon nitride materials for effective photocatalytic processes.

Enhanced photocatalytic ammonia oxidation over WO3@TiO2 heterostructures by constructing an interfacial electric field

WO3 nanorods and xWO3@TiO2 (WO3/TiO2 mass ratio (x) = 1−5) photocatalysts were synthesized using the hydrothermal and sol-gel methods, respectively. The photocatalytic activities of xWO3@TiO2 for NH3 oxidation first increased and then decreased with a rise in TiO2 content. Among them, the heterostructured 3WO3@TiO2 photocatalyst showed the highest NH3 conversion (58 %) under the simulated sunlight irradiation, which was about two times higher than those of WO3 and TiO2. Furthermore, the smallest amounts of by-products (i.e., NO and NO2) were produced over 3WO3@TiO2. The enhancement in photocatalytic performance (i.e., NH3 conversion and N2 selectivity) of 3WO3@TiO2 was mainly attributed to the formed interfacial electric field between WO3 and TiO2, which promoted efficient separation and transfer of photogenerated charge carriers. Based on the results of reactive species trapping and active radical detection, photocatalytic oxidation of NH3 over 3WO3@TiO2 was governed by the photogenerated holes and superoxide radicals. This work combines two strategies of morphological regulation and interfacial electric field construction to simultaneously improve light utilization and photogenerated charge separation efficiency, which promotes the development of full-spectrum photocatalysts for the removal of ammonia.

Photocatalysis Meets Piezoelectricity in a Type-I Oxygen Vacancy-Rich BaTiO3/BiOBr Heterojunction: Mechanism Insights from Characterizations to DFT Calculations.

It is a challenging task to design a piezoelectric photocatalyst with excellent performance under mechanical agitation instead of ultrasonic irradiation. Integrating vacancy defects into a heterojunction seems to be an effective strategy for synergistically increasing its piezo-photocatalytic performance. For this goal, a two-step hydrothermal method was adopted to architect a type-I oxygen-vacancy-rich BaTiO3/BiOBr heterojunction to surge the degradation of Rhodamine B (RhB) under the combined action of simulated sunlight irradiation and mechanical agitation. Various instrumental techniques demonstrated the formation of a BaTiO3/BiOBr heterojunction with high crystallinity. The existence of surface oxygen vacancies was confirmed by XPS and EPR tests. PFM results manifested that this heterojunction had excellent piezoelectric properties, with a piezoelectric response value of 30.31 pm V-1. Comparative experiments indicated that RhB degradation efficiency under piezo-photocatalysis over this heterojunction largely exceeded the total sum of those under piezocatalysis and photocatalysis. h+, ·O2-, and 1O2 were the dominant reactive species for RhB degradation. The improved separation efficiency of photogenerated charges was verified by electrochemical measurements. DFT calculations indicated that the polarization of BaTiO3 could affect the electronic band structure of BiOBr. This work will provide comprehensive insights into piezo-photocatalytic mechanism at a microcosmic level and help to develop new-styled piezoelectric photocatalysts.