Visible Light Photocatalytic Properties Research Articles

Preparation of K-doped g-C3N4 composite loaded on magnetic attapulgite and its degradation performance for malachite green

Visible-light-driven photocatalysis is a promising technology for the treatment of dye wastewater. In this work, a novel photocatalyst of K-doped g-C3N4 loaded on magnetic attapulgite (ATP) (Kω-g-C3N4@ATP-Fe3O4) with excellent visible light photocatalytic properties and stability were successfully prepared and characterized. The removal efficiency of Kω-g-C3N4@ATP-Fe3O4 for malachite green (MG) was studied, and the degradation mechanism was analyzed and proposed. It was found that the K5-g-C3N4@ATP-Fe3O4 photocatalyst possessed excellent degradation efficiency of over 98.0% for the MG dye wastewater under optimal conditions. Moreover, the K5-g-C3N4@ATP-Fe3O4 materials possessed good recyclability with a removal rate over 82% after 4 cycles. Under visible light condition, the K5-g-C3N4@ATP-Fe3O4 photocatalyst produce radicals of ·OH and ⋅O2− to degrade the MG dyes, which was supported by EPR and radical trapping experiments. In addition, the LC-MS analysis interpreted the degradation pathways and intermediates of MG in the solution. The findings in this work indicate that the prepared photocatalytic material has excellent degradation efficiency for MG and can be applied in dye wastewater treatment.

Photocatalytic Degradation of Crystal Violet on Cu, Zn Doped BiVO4 Particles.

Fabrication of codoped photocatalysts is a developing area of research. Herein, we explore the visible light photocatalytic properties of Cu, Zn codoped BiVO4 particles. Doping lower valent cations (Cu and Zn) makes the BiVO4 surface more acidic and enables us to target the basic crystal violet (CV) dye. The adopted hydrothermal protocol of synthesis results in the formation of Cu-Zn codoped monoclinic BiVO4 particles. Undoped monoclinic BiVO4, prepared by the same protocol, showed significant formation of oxygen vacancies. XPS analyses confirm the coexistence of Cu2+/Cu+ and Zn2+ dopants. Increased dopant percentage reduced oxygen vacancies. XRD indicates that Cu2+/Cu+ or Zn2+ dopants generally substitute Bi3+ in BiVO4. All photocatalysis activities for CV degradation are reported under near-neutral pH conditions. A typical codoped BiVO4 photocatalyst with 1% Zn and 2% Cu demonstrated the best CV degradation photocatalytic activity. The activity of this Zn, Cu codoped photocatalyst is better than that of pure, Zn-doped, and Cu-doped BiVO4 samples. Active species trapping experiments indicated the possible photocatalysis mechanism. The photocatalysts exhibited appropriate recyclability and photostability.

Characterization and photocatalytic properties of porous ZrO2/Al2O3 ceramic bead supported BiOI catalyst

Porous ZrO2/Al2O3 ceramic bead carriers were prepared through the gel-dripping method using sodium alginate as gelling agent with sucrose as pore-forming agent. The BiOI photocatalyst was loaded on the porous ceramic bead carrier with the solvothermal method. The effects of sucrose content and sintering temperature on the pore structure, porosity and compressive strength of the carriers were investigated. The influences of reaction time and reaction temperature on the microstructure and visible light photocatalytic properties of supported BiOI catalyst were also studied. The results show that, the porous ceramic bead with 30 wt% sucrose content sintered at 1300 °C exhibits a porosity of 71.60 % and a compressive strength of 5.06 MPa, which is suitable for the catalyst carrier. BiOI nanosheets assemble into microspheres with bonding force in the supported BiOI catalyst. BiOI microspheres distribute on the surface or in the pores of carriers. The supported BiOI catalyst prepared at 160 °C soaking for 6 h exhibits the highest degradation rate of 98.5 %. The microsphere diameter, loading amount, and photocatalytic activity of supported BiOI can be regulated through optimizing the reaction time and reaction temperature of solvothermal method. Compared with BiOI powder, the supported BiOI catalyst is easily recycled.

Impact of rare earth (La, Pr, Eu) impurities on the perovskite SrTiO3 for efficient photocatalytic activity

Owing to the growing demand for environmentally friendly technologies across a wide range of fields, including energy, environment and medicine, photocatalytic materials have gained a lot of interest in recent years. First-principles calculations were used in order to examine a variety of physical characteristics such as electronic density of states, structural, optical, and photocatalytic properties of pristine and rare-earth (RE = La, Pr, Eu) doped SrTiO3. The reported electronic band gap of pristine SrTiO3 is Eg = 3.03 eV, which is reasonably consistent with prior theoretical and experimental studies. On the other hand, related to Sr(1−x)RExTiO3, the obtained energy band gaps are 2.75 eV, 2.80 eV, and 2.90 eV associated with Eu-SrTiO3, Pr-SrTiO3, and La-SrTiO3 respectively. The narrowing of the electronic band gap of the studied systems is due to the incorporation of RE-doped SrTiO3, which greatly enhanced the visible light absorption spectra and photocatalytic properties. Thus, it can be concluded that adding RE elements to this kind of materials, is a suitable choice for optoelectronic and photocatalytic applications.

G-C3N4/PDI@ZnIn2S4 2D/2D organic–inorganic hybrid heterojunction with enhanced visible light photocatalytic property

In this study, we designed and fabricated novel g-C3N4/PDI@ZnIn2S4 2D/2D organic/inorganic hybrid heterojunctions consist of g-C3N4/PDI nanosheets and ZnIn2S4 nanosheets by a two-step-heating route followed by an oil-bath process for the first time. The synthesized heterojunctions were used as photocatalysts for the visible-light photodegradation of Rhodamine B (RhB), the composite photocatalysts displayed enhanced photocatalytic performance. Among them, the optimal photocatalyst exhibited significantly enhanced photocatalytic activity of up to 83.92 % after 120 min, which is nearly 7.0, 2.2, and 1.4 times higher than that of bare g-C3N4, g-C3N4/PDI, and ZnIn2S4, respectively. The enhanced photocatalytic activities can be attributed to the close interface contact and matched band structure between g-C3N4/PDI and ZnIn2S4, resulting in the formation of efficient heterojunctions, which accelerate the separation and transfer of photo-induced charges and improve the utilization of visible light. This work confirms the promising application prospects of g-C3N4/PDI@ZnIn2S4 photocatalysts in environmentalremediationfields.

Visible light photo catalytic and optical property evolution of combustion method prepared copper doped nickel ferrite nanoparticles

By using a simple microwave combustion technique, copper-doped NiFe2O4 spinel nanoparticles were formed. The XRD patterns demonstrated that Cu doping into NiFe2O4 spinel resulted in the creation of α-Fe2O3 secondary phase in addition to the cubic structure that already existed. Using SEM, morphological investigations revealed irregular shapes and severely agglomerated different grain boundaries. In an optical analysis, it was discovered that the band gap narrowed as the Cu2+ doping percentage raised. The octahedral site (Ni-O) and tetrahedral site (Fe-O) stretching modes of the Cu-doped nanoparticle structure were linked to bands at 548, 514, and 649cm-1 from FT-IR analysis. Cu-doped nanoparticles were examined for their enhanced photocatalytic degradation of RhB in visible light irradiation under atmosphere condition. The performance of pure NiFe2O4 as a photocatalyst was discovered to be greatly impacted by the Cu-doping. Additionally, the photo-catalytic effect was optimized (efficiency rose from 88.26 percent, x = 0-99.85 percent, x = 0.4) with the rise of Cu-doping into x=0.4. An in-depth discussion was had on the potential photocatalytic mechanism. The simultaneous improvement of photocatalytic activities serves as proof that Cu-doped NiFe2O4 spinel nanoparticles will perform well in multifunctional photochromic devices in future.

Synthesis and visible-light photocatalytic property of spinel CuAl2O4 for vehicle emissions.

Photodegradation of vehicle emissions is a promising approach for dealing with atmospheric pollution in road tunnels. In this research, copper aluminate nanoparticles (CuAl2O4) were prepared by the sol-gel method using copper nitrate, aluminum nitrate, and citric acid as precursor materials. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis spectroscopy to validate their structure, surface morphology, and optical properties, respectively. The XRD and SEM results confirm that the CuAl2O4 powder has a particle size of 20-37nm and exhibits a spinel-type structure. The upper limit of the stimulation wavelength in the UV-Vis diffuse reflectance spectrum is located at 725nm with a band gap (Eg) of about 1.50eV, which is suitable for effective visible-light degradation. Photocatalytic performance of the CuAl2O4 nanoparticles was analyzed by investigating the effects of light source, calcination temperature, and catalyst loading amount on the degradation of vehicle emissions (CO, HC, and NO). Best results were obtained under fluorescent light irradiation by CuAl2O4 nanoparticles calcined at 700°C. The optimum catalyst amount for decomposing CO, HC, and NO were determined as 0.5g, 0.5g, and 2g, respectively. Overall, the photocatalytic performance study verifies that spinel CuAl2O4 photocatalyst is a valuable material for next-generation technologies aimed at reducing harmful emissions from vehicles.

In Situ Construction of BiO(ClBr)(1-x)/2Ix-n Solid Solution with Appropriate Surface Iodine Vacancies for Synergistically Boosting Visible-Light Photo-Oxidation Capability.

A proposed BiO(ClBr)(1-x)/2Ix-n solid solution containing abundant iodine vacancies has been constructed through a facile solvothermal treatment strategy. Fascinatingly, the iodine-vacancy BiO(ClBr)(1-x)/2Ix-n solid solution exhibits an outstanding visible-light photocatalytic degradation property for the environmentally hazardous pollutants of methyl orange, tetracycline, and phenol solutions, which is credited to the synergistic effect of iodine vacancies and the solid solution. By manipulating the molar ratios of Cl, Br, and I, the band structure of the solid solution attained is controlled, enabling the samples to maximize the harvest of visible light and to possess strong oxidation features. More importantly, the construction of iodine vacancies is bound to modulate the local surface atomic structure and promotes the efficiency of the separation of photogenerated carriers. Given these, the microstructure and physicochemical and photoelectrochemical properties of the photocatalysts are fully characterized in a series. In addition, the iodine-vacancy BiO(ClBr)(1-x)/2Ix-n solid solution has a stable crystal structure that permits favorable recyclability even after multiple cycles of degradation. This study sheds light on the significance of the simultaneous existence of vacancy and the solid solution for the enhanced performance of photocatalysts and opens up new insights for sustainable solar-chemical energy conversion.

Construction of 2-aminobenzothiazole (ABT)-g-C3N4/WO3 composites with enhanced visible-light photocatalytic activity and properties

ABT doping improves the band gap and electron–hole separation efficiency of g-C3N4, and ethanol enhances the photocatalytic activity of ABT/CN/W composites.

Flexible PTh/GQDs/TiO2 composite with superior visible-light photocatalytic properties for rapid degradation pollutants.

Flexible fiber membranes for pollutant removal have received increasing attention due to their high adsorption performance and easy recycling characteristics. However, due to the lack of environmentally friendly regeneration, some adsorption membranes have low regeneration efficiency, especially in terms of chemical adsorption, so they lack reusability. This study prepares a series of conducting polymer [PAn (polyaniline) or PPy (polypyrrole) or PTh (polythiophene)] graphene quantum dots (GQDs, the size of GQDs is about 20 nm)/TiO2 ternary fiber membranes via a facile electrospinning method with chemical deposition. Remarkably, this creates an anatase TiO2 and π-conjugated system. The combination is beneficial to the photocatalytic degradation of organic pollutants, showing synergistic promotion in both the degradation rate and the degree of decomposition. The UV-vis test shows that the combination of GQDs broadens the optical response threshold of TiO2, from near ultraviolet region excitation to visible region excitation. At the same time, the conductive polymer load further reduces the energy required for photogenerated electron transfer, which theoretically improves the degradation effect. Photocatalytic degradation tests showed that the PTh/GQDs/TiO2 fiber membrane exhibited significant high photocatalytic activity of visible-light in the methylene blue (MB) and TC degradation. The degradation rate level is 92.90% and 80.58%, respectively and the MB removal is more than 4 times that of bare TiO2 membrane. After photocatalytic regeneration four times, the regeneration efficiency can be maintained above 95%. Notably, various experimental results show that the interface charge transfer mechanism between GQDs/TiO2 and PTh follows the Z-scheme heterojunction, which maximizes the retention of strong reducing electrons and oxidation holes. In the degradation, the active species of ·O2 - and ·OH, make different contributions in the photocatalysts, which oxidize and break down the pollutant molecules into small molecules and then to harmless substances. According to the electronegativity difference of the material itself, PTh acts as electron acceptor in the degradation system, and TiO2 fiber membrane doped with GQDs acts as electron donor. The present research, not only offers feasibility of the PTh/GQDs/TiO2 flexible fiber membrane as an environment-friendly catalyst, but also motivates researchers to develop flexible fiber materials for future photocatalytic technology.

Ga based Sillenite-TiO2 composite for efficient sunlight induced photo reduction of Cr (VI) and photo degradation of ampicillin

This work reports the design and development of an efficient sillenite based visible light photoactive Bi24Ga2O39–TiO2 (BGT) heterostructure. Structural and morphological studies based on X-ray diffraction (XRD) and high-resolution scanning electron microscopy (HRSEM) confirm the formation of combined phase as well the overall morphology of composite BGT. Additionally, X-ray photoelectron spectroscopy (XPS) results confirm the presence of Bi3+, Ga3+, Ti4+ & O2−. The composite exhibits a shift in the absorbance edge towards visible region of electromagnetic spectrum when compared to that of TiO2. Suitable band edge positions in the composite facilitate the formation of type-1 heterojunction enhancing visible light photocatalytic property. The photocatalytic activity is evident from photo reduction of Cr (VI) (95% reduction in 180 min). The composite also plays an improved and effective role in the degradation of persistent drug ampicillin-cloxacillin (AMC) with a rate constant of 0.02 min−1. Photocatalytic experiments conducted at different pH values showed higher performance at lower pH ∼3. Trapping experiments performed on the sample confirm the role of holes as the main active species during photocatalysis. Appreciable recyclability of BGT composite was noted with respect to AMC drug degradation.

Effect of Ni doping on the adsorption and visible light photocatalytic activity of ZnO hexagonal nanorods

Pristine and 1, 1.5, 2, 2.5 and 3 wt% Ni doped ZnO nanorods are prepared by hydrothermal technique as an effective photocatalyst for the removal of Malachite Green (MG) dye from aqueous media. Kinetic modelling of photocatalytic degradation and adsorption properties of the catalysts are done by pseudo first order (PFO), pseudo second order (PSO), fractal like psuedo first order (FPFO), fractal like psuedo second order (FPSO), elovich, exponential and intra particle diffusion (IPD) models. In contrary to the general trend, adsorption efficiency of ZnO is decreased while photocatalytic property got enhanced with doping. As-prepared catalysts are well characterised using XRD, FESEM, XPS, EDS, BET, UV and PL. This study points out the effect of Ni doping on the adsorption and visible light photocatalytic properties of ZnO nanostrutures via detailed kinetic modelling and explanation through various characterisation techniques and show cases their practical application in the field of waste water management. Water quality analysis was done post to degradation studies and the purified water samples have pH in the permissible range of drinking water which shows the efficient removal of dye molecules from the solution.

Enhanced visible-light-driven photocatalysis of in-situ reduced of bismuth on BiOCl nanosheets and montmorillonite loading: Synergistic effect and mechanism insight.

Various improvement strategies have been developed to enhance the visible light photocatalytic properties of materials. In these enhancement strategies, bismuth, a non-noble metal-based plasma metal, is deposited on the surface of the photocatalyst, which can improve the visible light response and photocatalytic performance of the photocatalyst. Herein, we constructed montmorillonite loaded BiOCl nanosheets with in situ reduced bismuth by one-step hydrothermal method. As for the results of TEM analysis, the in-situ reduced bismuth nanoparticles with diameters of 5-20nm were evenly distributed on the surface of BiOCl nanosheets. Due to the surface plasmon resonance (SPR) effect of semi metallic bismuth nanoparticles on the BiOCl nanosheets, the light absorption range of the modified photocatalyst was expanded and its absorption band gap (Eg) was reduced from 3.16eV (pure BiOCl) to 2.26eV. Besides, the results of dark adsorption experiments confirmed that the montmorillonite supporter greatly enhanced the adsorption capacity of the modified photocatalyst for pollutants. Moreover, the radical species trapping tests revealed that •O2- and h+ were the pivotal active agents in the pollutant degradation process. The visible light driven photocatalytic degradation rate of TCs and RhB by the modified photocatalyst was 3 and 4 times higher than that of pure BiOCl because of the synergistic effect of montmorillonite supporter and bismuth nanoparticles. The present work provides an innovative strategy for the great feasibility of fabricating low-cost clay and effective bismuth nanoparticles as a substitute for noble metal in environmental pollutants degradation.

Effects of gas phase ion irradiation and vacuum annealing on the visible light photocatalytic properties of WO3

Oxygen vacancies were introduced into tungsten oxide (WO3) rods by irradiation with H2+, He+ or Ar+ ions and/or vacuum annealing. The surface chemical bonding states and visible light photocatalytic properties of these materials were subsequently assessed. Although the irradiated surfaces were contaminated with carbon and silicon species during ion irradiation, vacuum annealing at 500 °C decreased the extent of carbon contamination and increased the concentration of lattice oxygen species related to a surface WO3-x phase. The irradiated WO3-x rods exhibited low photocatalytic efficiencies during the degradation of rhodamine 6G compared with pristine WO3 rods, possibly due to the existence of contamination and oxygen vacancies. Vacuum-annealed WO3-x rods having a green coloration exhibited high photocatalytic efficiency as a result of enhanced visible light absorption and the low concentration of both surface contamination and vacancies.

Nitrogen-doped graphyne/BiOBr nanocomposites: In-situ sonochemical synthesis and boosted photocatalytic performance

In this study, a facile in-situ sonochemical synthesis process is developed to construct nitrogen-doped graphyne/BiOBr composites. Multiple techniques are implemented to characterize the structures, morphologies, electronic and optical properties, and photocatalytic activity of the as-prepared samples, including X-ray powder diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, Raman, and X-ray photoelectron spectroscopy, etc. The results indicate that the wrinkle-like layer structure of N-graphyne enwinds around the sheet structure of BiOBr. Compared to pristine BiOBr, N-graphyne/BiOBr composites present superior visible-light response, higher specific surface area, and more significant separation of photoinduced charge carriers verified by Brunauer-Emmett-Teller, UV–vis absorption spectroscopy, instantaneous photocurrent, electrochemical impedance spectroscopy, and photoluminescence, thus presenting more pronounced visible-light photocatalytic properties on N2 fixation and decomposition of pollutants. The optimal ratio of N-graphyne in N-graphyne/BiOBr composites is screened out for the photocatalytic decomposition of rhodamine B, levofloxacin, methylene blue, and nitrogen fixation under visible light illumination. Furthermore, the main active species are demonstrated as hole and O2– during photocatalytic degradation and the stable performance of is also observed for N-graphyne/BiOBr composites. The present research demonstrates that N-graphyne embellishment is an effective strategy to enhance the photocatalytic efficiency of BiOBr, which can be broadened as an excellent co-catalyst for decoration of other semiconductors.

Natural Diatomite Supported Zirconium-Doped TiO2 with Tailoring Band Structure for Enhanced Visible-Light Photocatalytic Properties.

The development of economically applicable, highly efficient and low cost photocatalytic materials has always been a challenge. In this work, we report a zirconium doped TiO/diatomite (ZrTD) composite with enhanced visible light-induced photocatalytic activity. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, UV–VIS diffused reflectance spectroscopy, high-performance liquid chromatography-mass spectrometry, photoluminescence and X-ray photoelectron spectroscopy, respectively. The optimal doping ratio of zirconium into TiO was obtained at 3% (3%ZrTD composite), and the degradation rate constant of which tetracycline (TC) is up to around 8.65 times higher that of zirconium doped TiO. In addition, zirconium doping introduces the impurity levels of Zr 3d and oxygen vacancies into the lattice of TiO, resulting in broadening the light absorption range, reducing the band gap, and improving the separation efficiency of photogenerated electron-hole pairs, thus endowing with visible light photocatalytic properties. Moreover, both the photogenerated holes (h) and superoxide (•O) radicals are responsible for the degradation process of TC, and a possible degradation pathway and the corresponding intermediate products of TC by ZrTD composite are also proposed in detail.

Effect of temperature on the synthesis of g-C3N4/montmorillonite and its visible-light photocatalytic properties

AbstractGraphite phase carbon nitride (g-C3N4) is a non-metal semiconductor material with a suitable band gap (2.7 eV) for visible photocatalysis. However, the high cost of relevant synthesis methods and poor adsorption performance have limited its practical applications. The objective of the present study was to mitigate these problems by synthesizing the g-C3N4 in the presence of exfoliated montmorillonite (Mnt). Compared with bulk montmorillonite, the specific surface area of exfoliated two-dimensional Mnt layers was significantly increased. As a result, the light transmittance of the lamella improved noticeably due to the fact that a freshly exposed surface had a large number of active reaction sites, making Mnt an excellent carrier for the photocatalyst g-C3N4. In order to improve the photocatalytic performance of g-C3N4, a series of g-C3N4/Mnt composites was prepared by a wet chemical method using Mnt nanolayers as the matrix. X-ray diffraction, infrared spectroscopy, Brunauer-Emmett-Teller nitrogen adsorption/desorption, transmission electron microscopy, and ultraviolet-visible diffuse reflectance spectroscopy were used to analyze the phase structure, the chemical bonds, the specific surface area and pore sizes, the morphology, and the light absorption characteristics of the composites, respectively. Rhodamine B (RhB) served as the target dye to test the photocatalytic degradation performance of the composites under visible light. According to the findings, the surface of the Mnt nanolayers was densely and uniformly covered by g-C3N4, forming a multi-layered stack structure. An increase of the calcination temperature improved the crystallinity of g-C3N4, leading first to densification and then to relaxation of the layered composite structure. Conversely, the band gap of the composite gradually decreased from 2.56 to 2.4 eV. Furthermore, temperature exposure changed the photocatalytic performance of the composite drastically. While the largest photocatalytic activity was observed at 610°C, it started to decrease with further heating of the composite. The complete degradation of RhB solution occurred after 2 h of visible light irradiation. The findings of the current study provide a scientific basis for the synthesis of a new generation of photocatalysts.

Visible light photocatalytic and magnetic properties of V doped α-Fe2O3 (VFO) nanoparticles synthesized by polyol assisted hydrothermal method

Vanadium-doped α-Fe2O3 nanoparticles (VFO nanoparticles) were prepared by polyol-assisted hydrothermal method. The impact on the structure, optical, magnetic and photocatalytic properties of α-Fe2O3 nanoparticles were studied by varying the vanadium concentration from 1 to 5%. XRD analysis confirms the presence of hematite phase with hexagonal structure and estimates the nanocrystals size as ∼26–38 nm. FESEM and TEM reveal the formation of 3D flower-like morphology bundled with 2D nanoflakes. The estimated band gap energy was in the range 2.01 eV–2.12 eV. XPS study shows the presence of vanadium in V4+ oxidation state in VFO nanoparticles. VSM study shows a non-saturated hysteresis loop with weak ferromagnetic behavior for all the VFO nanoparticles. 5% V doped α-Fe2O3 nanoparticles (5%VFO nanoparticles) exhibited superior visible light driven photocatalytic activity compared to other samples.

Enhanced visible-light photocatalytic properties of SnO2 quantum dots by niobium modification

The incorporation of transition metal elements is an effective route to enhance the photocatalytic properties of semiconductors. Tin oxide (SnO2) has a wide band gap of 3.6 eV, which inhibits its applications as visible-light photocatalysts. In this work, niobium-modified SnO2 quantum dots (Nb-SnO2 QDs) are synthesized by a one-step hydrothermal method. The crystal structures and optical properties of the Nb-SnO2 QDs are characterized and the photocatalytic performances are evaluated by the degradation of organic contaminants under visible-light illumination. The rate constant of Nb-SnO2 QDs increases 2.34 times as that of pristine SnO2 QDs in MO degradation. The improved photocatalytic properties are ascribed to the modified band structure by the transition metal. The main active radical is determined to be O2− in the photocatalytic process. The first principle computational models are established based on the experimental characteristics of Nb-SnO2 QDs. The calculation reveals that Nb incorporation brings an impurity energy level in the band structure, which is originated from the 4d orbital electrons of Nb atoms.

Synergistic effect of Ni doping and oxygen vacancies on the visible light photocatalytic properties of Ag2O nanoparticles

Chemisorbed oxygens on photocatalysts can be photo-excited and favorably generate reactive oxygen species like superoxide radicals. In the present research, we prepare oxygen vacancy (OV) mediated and Ni-doped Ag2O nanoparticles by similar hydrothermal protocols. Doping Ag2O by the higher oxidation state Ni enhanced the chemisorbed oxygen on the surfaces of the prepared nanoparticles but reduced the OV proportion. The inclusion of OVs widened the bandgap of Ag2O nanoparticles, which was also validated by density functional theory (DFT) calculations. DFT formation energy calculations indicated that the dopant Ni atom could be substituting an Ag site in the Ag2O lattice. X-ray diffraction (XRD) analysis showed that doping caused Ag2O lattice contraction possibly due to the smaller Ni substituting the larger Ag atom. X-ray photoelectron spectroscopy (XPS) analysis showed that OV-mediated Ag2O nanoparticles have a negative conduction band position and Ni-doping slightly narrowed the bandgap along with a more positive valence band position. DFT calculations also showed shifting of the density of states (DOS) due to Ni doping in OV Ag2O. Both OV mediated and Ni-doped Ag2O nanoparticles photocatalyzed ciprofloxacin (CIP) degradation under visible light irradiation. Increased chemisorbed oxygen due to Ni-doping enhances the CIP degradation rate.