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Graphitic carbon nitride (gCN) has shown great potential in photocatalysis. Developing suitable cocatalysts is a critical way to enhance gCN's photocatalytic performance. In this paper cobalt–nickel bimetallic phosphide (CoNiP) was used as a cocatalyst to modify gCN. A gCN/CoNiP composite was successfully prepared by a simple hydrothermal method. XRD, XPS, SEM, UV-vis DRS, and PL characterization studies showed that a Schottky junction-like structure was constructed between gCN and CoNiP, which intensified the visible light response, enhanced the charge transfer rate and prohibited the recombination of photogenerated carriers, thus significantly improving gCN photocatalytic activity. Under simulated sunlight, the removal efficiency of methylene blue (10 mg L−1) was 97.8% by 120 min of irradiation, 44.6% higher than that of gCN. The quenching experiment showed that ˙O2−, ˙OH and h+ were the main active species. Based on the above points, the possible mechanism of photocatalysis was deduced. [ABSTRACT FROM AUTHOR]

In this paper, three-dimensional TiO2 nanoflowers (NFs) were prepared by a facile hydrothermal method, and Ag3PO4 was grown in situ following alkali treatment to design and synthesize a Ag3PO4/OH/TiO2 catalyst with excellent photocatalytic activity under visible light. The test results show that the photocatalytic degradation performance of TiO2 NFs after alkali treatment and Ag3PO4 loading is significantly improved. This is because the alkali treatment and the introduction of Ag3PO4 can provide a large amount of –OH, which can be converted to ˙OH under UV irradiation, followed by an increase in the number of active radicals to enhance the photocatalytic degradation performance. Meanwhile, the introduction of Ag3PO4 can effectively improve the light absorption ability of the photocatalyst. Moreover, the in situ growth of Ag3PO4 on TiO2 NFs can construct a high-quality Ag3PO4/TiO2 heterojunction to promote the charge separation and transport. Therefore, the degradation rate of Ag3PO4/OH/TiO2 can reach 90% after 30 min for degrading 3 mg L−1 RhB under visible light. The Ag3PO4/OH/TiO2 photocatalyst designed in the present work provides a new tool for the degradation of organic dyes. [ABSTRACT FROM AUTHOR]

Enhancing the piezoelectric polarization strength of materials to promote the photogenerated carrier separation is of great significance for piezoelectric polarization-assisted photoelectrochemical (PEC) water splitting. In this paper, P-BiFeO3 composite photoelectrodes were synthesized by modifying BiFeO3 photoelectrodes with phosphate ions. The maximum photocurrent density of the P-BiFeO3 composite photoelectrodes could reach 0.87 mA cm−2 at 1.23 V vs RHE, which is significantly enhanced compared to the BiFeO3 photocurrent. The enhanced photoelectrochemical activity of the phosphate ion-modified BiFeO3 photoelectrodes may be attributed to the increased visible light absorption and larger active area due to the presence of phosphate groups. Furthermore, the photocurrent density of the P-BiFeO3 composite photoelectrodes after the introduction of the piezoelectric polarisation field reached 2.58 mA cm−2 at 1.23 V vs RHE, which was 2.2 times higher than that of BiFeO3 (1.17 mA cm−2). The presence of phosphate groups on the surface of BiFeO3 photoelectrodes can improve their asymmetry and increase their piezoelectric polarisation intensity, further enhancing the PEC water splitting performance of the material. This study provides a strategy for the design of highly active photoanodes with ionic modification to enhance the piezoelectric polarisation of the material to improve PEC water splitting. [ABSTRACT FROM AUTHOR]

BiOCl has garnered considerable attention recently. However, its relatively wide bandgap and poor separation efficiency of charge carriers limit its application in the visible light range. Introducing oxygen vacancies (OVs) and constructing heterojunctions are both considered as viable modification approaches. In this study, oxygen vacancy-rich BiOCl/Bi24O31Cl10 heterojunctions were synthesized using glycine as the fuel by a one-pot self-propagation method. Variations in the amount of fuel led to differences in OV concentration and heterojunction composition in the prepared samples. The XRD pattern, FTIR spectra and EDS confirmed the formation of BiOCl/Bi24O31Cl10 heterojunctions. The XPS and ESR spectra proved the existence of oxygen vacancies. The BET results showed that the sample prepared with an appropriate amount of glycine exhibited a larger specific surface area. The most effective OVs-BiOCl/Bi24O31Cl10 composite demonstrated improvements in degrading rhodamine B (RhB), showing 8.09 and 17.96 times greater efficiency compared to BiOCl and Bi24O31Cl10, respectively. It achieved 93% dye degradation within 30 minutes. [ABSTRACT FROM AUTHOR]

Latent fingerprint (LFP) detection is an important tool in criminal offense detection. Nowadays, ultraviolet (UV) excited visible emission phosphors are widely used in LFP detection; however, due to the shortcomings of UV excitation (λex < 270 nm) such as low power, high price, and susceptibility of visible light to the influence of natural light, their application in LFP detection is restrained. Here, a new idea is proposed: the use of blue light-excited near-infrared (NIR) emitting phosphors as a tool for fingerprint detection visualization. To this end, in this work, a series of blue-excited (λex = 467 nm) NIR phosphors Ca(1−x)SrxO:Eu2+ (x = 0–0.2) were designed based on CaO:Eu2+ by using the crystal field engineering strategy. When x = 0.2, the luminescence center is red-shifted from 733 nm to 783 nm, and the full width at half maximum (FWHM) is broadened from 100 nm to 156 nm, and the red-shift and broadening of the spectrum greatly improve the accuracy of fingerprint detection. Finally, Ca0.8Sr0.2O:0.1%Eu2+ gives high-quality visualized fingerprints in LFP detection, which is a good solution to the problems faced by UV-excited visible-emitting phosphors in LFP detection. Not only that, a NIR phosphor-converted light-emitting diode (NIR pc-LED) was prepared by combining Ca0.8Sr0.2O:0.1%Eu2+ with a blue LED chip, which was verified to have the potential for applications in biological tissue penetration and night vision illumination. This work introduces a new idea for the detection of a LFP and demonstrates that rationalizing the local structure around Eu2+ is an effective strategy for exploring Eu2+-doped NIR luminescent phosphors. [ABSTRACT FROM AUTHOR]

The development of advanced efficient and durable non-precious metal-based anode catalysts for photo-assisted direct methanol fuel cells remains a significant challenge. In this study, Ce-doped Co3O4 (Ce–Co3O4) was prepared by a three-step process involving hydrothermal synthesis, cation exchange and calcination. The introduction of Ce can not only induce more Co3+ with oxidation properties, but also expand the light absorption range and improve the separation efficiency of photogenerated electron–hole pairs. In an alkaline solution and under visible light irradiation, Ce–Co3O4 showed high current density (31.4 A g−1), high photo-response current (3.52 A g−1) and good long-term stability (the current density retention was 82% after 13 h under visible light irradiation). The reaction mechanism for the photo-assisted methanol oxidation was investigated by a series of optical characterization studies (UV-vis diffuse reflectance spectroscopy, Mott–Schottky, photoluminescence spectroscopy, and electron paramagnetic resonance). The results indicated that the strong oxidative photogenerated hole (h+), ˙OH, and ˙O2− were beneficial for the oxidation of methanol and COads. This study provides a good idea for the design of efficient non-precious metal based anode catalysts for photo-assisted direct methanol fuel cells. [ABSTRACT FROM AUTHOR]

Visible-light active heterogeneous photocatalysts offer various advantages owing to their ability to exploit clean, renewable, and economically viable visible light as a driving force. This study aims to develop such photocatalysts by incorporating various loadings (10, 20, and 30 wt%) of bismuth tungstate (Bi2WO6 or BWO) into graphitic carbon nitride (g-C3N4 or CN) nanosheets. The CN nanosheets and BWO nanomaterials are synthesized using an eco-friendly hydrothermal method. The objective is to evaluate the photocatalytic activity of these catalysts for the Knoevenagel condensation reaction under 12 W blue LED light (low power), aiming to outperform the activity of pure CN. Various characterization methods, including XRD, UV-vis DRS, FTIR, PL, XPS, and TEM, are employed to analyze the catalysts. The study specifically focuses on the performance of the various BWO loading percentages on CN nanosheets. Among those, 20 wt% BWO loaded CN achieves a yield of 80% with minimal activity decline over five recyclability cycles. Furthermore, this study identifies that BWO/CN follows a Z-scheme pathway, enhancing the photocatalytic performance and facilitating organic transformations. Scavenging experiments confirm the formation of radicals during photocatalysis, validating the proposed mechanism and providing crucial mechanistic insights. Ultimately, this research seeks to highlight BWO/CN as a promising, environmentally friendly photoactive substance with significant potential for effective photocatalytic use. To our knowledge, this is the first study to use BWO/CN catalysts for the Knoevenagel condensation reaction under blue LED irradiation. [ABSTRACT FROM AUTHOR]

This method describes the iron-promoted amidation of dioxazolone under visible light to obtain aromatic/alkyl substituted amides. The nitrogen radicals formed during this process undergo hydrogen atom transfer (HAT) to form amides through the proton provided by HBpin. This reaction eliminates the need for external chemical oxidants and expensive photocatalysts, and exhibits compatibility with various aryl/alkyl substituted derivatives. This method has good prospects for application and development in organic synthesis and medicine. [ABSTRACT FROM AUTHOR]

In this work, based on the electrostatic adsorption theory, a direct Z-scheme NH2-UiO-66/BiOCl composite photocatalyst was prepared by a one-step solvothermal method with NH2-UiO-66 embedded on the smooth surface of flower-like BiOCl without additional chlorine source to form a close contact interface. The photocatalytic degradation of tetracycline hydrochloride (TCH) of 1.0-NH2-UiO-66/BiOCl(1.0-NUBC) prepared under simulated sunlight was 1.63 times and 78.84 times that of pure BiOCl and pure NH2-UiO-66, respectively. The reason for the enhanced photocatalytic performance may be that electrostatic adsorption promotes the homogeneous and orderly synthesis of heterogeneous structures, significantly increasing the ratio of NH2-UiO-66/BiOCl surface, which not only improves the visible light response range but also promotes the formation of the interface electric field between NH2-UiO-66 and BiOCl interface. The separation and transfer of the photogenerated electron–hole pairs are greatly promoted. Therefore, this study provides an effective way for the synthesis of BiOCl/MOF composites and has a good application prospect. [ABSTRACT FROM AUTHOR]

Promoting the separation of photoelectrons and holes can enhance the photocatalytic performance of photocatalysts. The combination of photocatalysts with piezoelectric materials is an effective way to improve the photocatalytic performance. In this paper, the heterogeneous structure of PZT/Ag2O is proposed, which can effectively improve its photocatalytic degradation performance through the piezoelectric effect. RhB degradation experiments were conducted under ultrasonic vibration and visible light irradiation to evaluate the photocatalytic performance of PZT/Ag2O. It is worth noting that PZT/Ag2O showed excellent piezo-/photocatalytic activity, and the degradation rate of RhB within 60 min was 96.31%, which was higher than those achieved under ultrasonic vibration (55.98%) and visible light irradiation (65.14%). The improved performance is due to the heterojunction construction widening the optical response range, while the piezoelectric effect provides a built-in polarization field to improve the separation efficiency of photogenerated electrons and holes. This study provides an efficient and feasible piezo-/photocatalyst for the treatment of pollutants. It is helpful to understand the mechanism of the piezoelectric effect and improve the photocatalytic performance. [ABSTRACT FROM AUTHOR]

Comprehensive strategies with the development of advanced materials are required for the remediation of water and land pollution to protect the environment and human health. In this regard, iron oxide catalysts are recognized as preferable catalysts for the heterogeneous photo-Fenton process, which is an efficient technique for degrading organic pollutants in waste water. The present study discusses the photocatalytic performance of iron oxide-based catalysts synthesized from industrial waste red mud for methylene blue degradation under visible light irradiation. XRD studies confirmed the formation of a pure α-Fe2O3 (hematite) phase, whereas the doping of iron oxide with Mn, Cu, and Ce was ascertained by XPS analysis. 3 wt% Cu doped iron oxide with a TOC value of ∼84.7% showed the best removal efficacy to the tune of ∼91% within 60 min of visible light irradiation. Impedance data supports the enhanced charge separation in metal doped α-Fe2O3, which improves the photocatalytic performance. A similar trend was observed in photo-electrochemical (PEC) properties, where Cu doped Fe2O3 showed 2 times higher photocurrent than the bare one. Based on scavenging tests, electrons and hydroxyl radicals (˙OH) were shown to be major players in the photodegradation of pollutants under visible light. A probable mechanism explaining the enhanced e−/h+ pair separation and migration was proposed by examining electrochemical properties. This work has significant implications for wastewater treatment with the efficient use of industrial waste red mud as a cost-effective resource. [ABSTRACT FROM AUTHOR]

It is essential to design and fabricate semiconductor-based photocatalysts with excellent activity to split H2O into H2 and O2 using sunlight because of the depletion of fossil resources and environmental pollution. LaVO4 is a visible light catalyst with a narrow band gap, satisfactory stability, and a low price. Therefore, in this work, alkali metal-doped LaVO4 was manufactured. Alkali metal-modified LaVO4 was prepared by a hydrothermal method as a photocatalyst for water splitting under visible light illumination, and a series of characterizations was carried out. The results showed that alkali metal doping improved the catalytic performance of pure LaVO4 and mainly optimized the hydrogen and oxygen production of Na-doped LaVO4 so that a maximum H2 and O2 evolution of 2.83 and 0.71 mmol g-1 h-1, respectively was obtained. The superior photocatalytic activity of Na-doped LaVO4 was mainly attributed to synergistic effects, including the extended visible-light response and improved charge separation. This study provides a new idea for the design of a highly efficient LaVO4-based water-cracking photocatalys.t. [ABSTRACT FROM AUTHOR]

The fabrication of environmentally friendly materials for wastewater remediation represents a promising approach. Thus, we present the fabrication of nanostructured CoFe2O4 (CF) particles entangled within a hydrogel-based matrix composed of carboxy methyl cellulose-psyllium-RGO (CPRHG/CF). The functionality, composition, and nature of the fabricated composite were characterized using FTIR, XRD, and XPS techniques. Furthermore, the internal and surface morphology was analyzed through FE-SEM and HR-TEM imaging. To assess the photo activity, UV-Vis and photoluminescence (PL) spectroscopy were employed, confirming that CPRHG/CF exhibits significant potential for light absorption in the visible spectrum while minimizing the charge recombination rate. The fabricated CPR/CFHG composite hydrogel was employed for the removal of pharmaceutical effluent, tramadol (TMD), via both adsorption and photocatalysis processes. In batch adsorption experiments lasting 2 hours, the composite hydrogel demonstrated impressive adsorption efficiency of 92.93% and a maximum adsorption capacity of 89.97 mg g-1. Subsequently, during photocatalytic treatment under 1 h of solar illumination, approximately 90.36% of the TMD was successfully degraded. The degradation process followed a pseudo-firstorder kinetics model with a rate constant (k1) of 0.0380 min-1. Furthermore, the investigation of reactive oxygen species (ROS) has identified superoxide radicals (O2 -) as the major species responsible for the degradation process, which was confirmed through radical scavenging experiments. [ABSTRACT FROM AUTHOR]

The most effective approach to develop new photocatalysts involves solar activation and prevention of the recombination of photogenerated hole–electron pairs. To achieve these goals, in this work, a series of bismuth oxyiodide and graphene oxide (BiOI/GO) composites were synthesized by a simple ex situ method. The structural, morphological, optical, and electrical properties of the synthesized compounds were thoroughly investigated. The photooxidation reaction of NO in the gas phase under visible light irradiation was used to assess the photocatalytic activity of BiOI/GO composites. The results showed that a small amount of GO significantly improved the photocatalytic activity. The BiOI/GO-0.5% sample prepared with 0.5 wt% GO showed the highest NO conversion (∼100%), indicating excellent photocatalytic stability after four continuous irradiation cycles and a high selectivity of 97% for nitrate ion formation. The increase in photocatalytic activity was mainly related to increased light absorption, high specific surface area, and better separation of light-generated charges. The use of chemical scavengers contributed to clarifying certain aspects of the possible photooxidation process of NO, which demonstrated that superoxide radicals (˙O2−) could be the main factor responsible for the photodegradation of NO by BiOI/GO-0.5%. [ABSTRACT FROM AUTHOR]

TiO2/rGO (TG) composites were synthesized using a hydrothermal reduction method, with titanium dioxide and graphene as the starting materials. Subsequently, dye-sensitizing titanium dioxide/graphene photocatalytic composites, named DTG and APTG, were prepared by covalently attaching C.I. Direct Black 17 or C.I. Acid Violet 3 dye onto TG. The composites were characterized using FTIR, TEM, UV-vis DRS, EDS, and Raman spectroscopy. The EDS surface scanning results of APTG and D2.70TG composites have shown that Ti and S atoms are uniformly distributed on the graphene sheets. The presence of characteristic peaks for S2p and N1s near 166 eV and 399 eV in D2.70TG and APTG was intensified compared to those of TG composites. The grafting rate reached its peak when the amount of C.I. Direct Black 17 was 2.70 and the fixed amount of TG was 0.1 g. The UV-vis diffuse reflectance spectroscopy study results demonstrated a shift in the response range to visible light after dye modification for DTGs and APTG. Photocatalytic experiments showed that D2.70TG was capable of removing over 99% of MB within 1 hour. Furthermore, after 5 cycles of photocatalytic experiments, the removal rate of MB remained at above 95%. [ABSTRACT FROM AUTHOR]

This study developed an efficient photocatalyst for hydrogen production, consisting of CdS nanorods and the CoTPPBr4 co-catalyst. The synthesized photocatalyst was characterized using a suite of techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), photoluminescence (PL) spectroscopy, and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). Additionally, transient photocurrent response and electrochemical impedance spectroscopy (EIS) were carried out to further probe the material's properties. Our findings demonstrate that the CoTPPBr4 co-catalyst significantly enhances the photocatalytic H2 evolution efficiency under visible light irradiation. Notably, among the tested photocatalysts, a 12.5% CoTPPBr4/CdS composite exhibited the most superior photocatalytic performance, achieving a hydrogen production rate of 41.3 mmol g−1 h−1, which is 4.1 times higher than that of pristine CdS. The introduction of CoTPPBr4 effectively facilitates charge transfer within CdS, enhances the separation efficiency of light-induced electron–hole pairs, and boosts the surface H2-evolution kinetics. This research not only introduces a promising photocatalyst for visible light-driven hydrogen production but also provides a way for the development of highly efficient and stable CdS-based hybrid semiconductor nanocomposites suitable for diverse photocatalytic applications. [ABSTRACT FROM AUTHOR]

The presence of antibiotics in aquatic systems poses a significant risk to both the ecological balance and human health. To address this issue, the development of advanced photocatalytic materials capable of efficiently treating antibiotic-contaminated wastewater is imperative. In this investigation, we successfully synthesized nitrogen–phosphorus co-doped carbon dots (NPCDs) modified (001) TiO2/Ti3C2Tx composites via a series of uncomplicated hydrothermal reactions, ensuring visible light responsivity. Comprehensive characterization of the composite photocatalysts was conducted using XRD, FT-IR, N2 adsorption, SEM, TEM, XPS, UV-Vis DRS, and PL techniques. Subsequently, the photocatalytic performance was assessed through the degradation of tetracycline hydrochloride (TC) and ceftiofur sodium solutions under visible light irradiation. The optimized composites exhibited remarkable photocatalytic degradation efficiencies of 93.4% and 75.5% for TC and ceftiofur sodium, respectively, under visible light, following quasi-primary kinetic behavior. Reactive free radical capture experiments highlighted the predominant roles of ˙O2− and ˙OH species in the photocatalytic degradation process. Additionally, we proposed plausible mechanisms governing photocatalytic degradation based on the obtained results. The heightened photocatalytic reactivity arises from the efficient transfer of photogenerated electrons through the NPCDs → TiO2 →Ti3C2Tx pathway, a mechanism that effectively facilitates the separation and transfer of photogenerated charge carriers. [ABSTRACT FROM AUTHOR]

This work reported an Aux/BaTiO3 plasmonic photocatalyst with superior photocatalytic CO2 reduction performance under visible light irradiation compared to ordinary BaTiO3. This is mainly attributed to the introduction of plasmonic Au NPs, which improves the separation efficiency of photogenerated carriers and further enhances the photocatalytic CO2 reduction performance of the catalyst through the hot electrons generated by the LSPR effect. The photocatalytic conversion rates of CO2 to CO and CH4 by Au5/BaTiO3 reached 62.3 and 20.7 μmol g−1 h−1, respectively. [ABSTRACT FROM AUTHOR]

The development of clean and sustainable nitrogen-fixing methods has always attracted significant attention for decades. In this work, we investigated a strategy to enhance the N2 photo-fixation performance of titanium dioxide (TiO2) films by leveraging the synergistic effect between photon localization effects and iron (Fe) doping. Introducing Fe ions into TiO2 broadens its light absorption spectrum, making it extend into the visible light range, while improving charge separation capabilities. Our findings revealed that the photocatalytic ammonia generation of Fe-doped TiO2 (FT) catalysts, with a Fe3+ concentration of 6%, could reach up to 1.5 times that of pure TiO2. Besides, the photon localization effect of the SiO2 opal photonic crystals (SOPC) could enhance the light harvesting efficiency of the photocatalysts. By coupling the SOPC layer and nanocrystalline FT films, the N2 photo-fixation performance of FT/SOPC composite membranes was further promoted to 55.6 mmol g-1 h-1. This study offered a promising route for nitrogen fixation using solar energy. [ABSTRACT FROM AUTHOR]

NiO nanoparticles were synthesized and modified with Ni0 in the form of Ni/NiO blend and supported on a porous diatomite substrate, forming hybrid structures of NiO/D and Ni@NiO/D with enhanced photocatalytic performances. The obtained structures were applied for the effective oxidation of acephate pesticides under visible light. The obtained results demonstrated enhancement in the catalytic performance of Ni@NiO/D compared to NiO, Ni/NiO, and NiO/D structures. The full oxidation of AC (50 mg L−1) was determined after 40 min using Ni@NiO/D at doses of 0.5 g L−1. Moreover, the complete mineralization of AC molecules over Ni@NiO/D was detected after 70 min, considering the complete removal of TOC and the detection of essential inorganic anions (NO3− (7.6 × 10−5 mol L−1), SO42− (1.7 × 10−5 mol L−1), and PO43− (5.4 × 10−5 mol L−1)). The oxidation pathway was illustrated by considering the estimated intermediates and the detection of hydroxyl radicals as main oxidizing species. The toxicity of untreated AC solutions and degraded intermediates was analyzed by assessing their inhibitory effect on Vibrio fischeri. Samples that underwent partial oxidation during their initial examination exhibited a greater degree of toxicity (65.3% inhibition) compared to AC. Nevertheless, a sample subjected to an 80 minute treatment exhibited neglected toxicity (1.4% inhibition). The combination of the diatomite substrate and Ni0 doping enhanced the adsorption and photocatalytic properties of NiO. [ABSTRACT FROM AUTHOR]

Based on the anion exchange strategy, a novel Bi2S3/BiOCl0.1Br0.9 S-scheme heterojunction was prepared via a facile one-step low-temperature water bath method for the first time. In this process, 2D Bi2S3 nanosheets were controllably grown on the surface of a 3D hollow BiOCl0.1Br0.9 solid solution. Under visible light irradiation, the as-prepared 3BS-BCB exhibited a remarkable photocatalytic degradation efficiency of 99.67% toward rhodamine B (Rh B) within 140 min, which is approximately 3.57 times higher than that of the BiOCl0.1Br0.9 solid solution alone. The enhanced photocatalytic performance is attributed to the formation of an interfacial electric field (IEF), which accelerated the separation rate of photoinduced electron–hole pairs and coupled the strong redox ability of both the semiconductors. Moreover, the photosensitive effect of Bi2S3 extended its light absorption range, increasing the yield of photogenerated charge carriers. Such thermodynamic and kinetic compatibility is the fundamental reason for the enhanced photocatalytic efficiency. This study provides new insights into the design of S-scheme heterojunction photocatalysts with visible light response and high redox ability based on wide-band gap semiconductors. [ABSTRACT FROM AUTHOR]

A novel Fe–RGO/TiO2/PTFE photocatalytic composite membrane was developed for the purification of MB wastewater. The properties of the prepared membranes were characterized using XRD, SEM, FT-IR spectroscopy, the BET method, and water contact angle, membrane flux, and BSA adsorption measurements. The photocatalytic properties of the surface-modified membranes were investigated in filtration experiments using MB as a representative organic contaminant. The results of the experiments showed that the Fe–RGO/TiO2 particles were securely loaded onto the surface of the PTFE membrane, demonstrating excellent chemical stability of the composite membrane. The incorporation of Fe3+ inhibited the agglomeration of TiO2 particles and enhanced the photocatalytic reaction rate. The introduction of RGO could broaden the photoresponsive range of TiO2, increase the specific surface area of the photocatalyst, introduce a large number of hydrophilic groups to enhance the hydrophilicity of the composite membrane, and subsequently increase the membrane flux. The MB wastewater was treated with the Fe–RGO/TiO2/PTFE composite membrane system for 3 h and the removal rate of MB reached 95.8% and 60.1% under UV and visible light, respectively. Reaction kinetic analysis indicated that the removal process of MB wastewater by Fe–RGO/TiO2/PTFE involves an adsorption–degradation–filtration synergy mechanism. [ABSTRACT FROM AUTHOR]

Spherical BiOI/UiO-66(Zr) composite materials were synthesized using a solvothermal method. The compositions, structures, and optical properties of the materials were characterized through X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller measurements, and UV-Vis spectroscopy. The experimental investigation involved the activation of persulfate (PMS) by BiOI/UiO-66(Zr) for the visible light degradation of Acid Orange II. The effects of the BiOI to UiO-66(Zr) mass ratio, BiOI/UiO-66(Zr) dosage, PMS concentration, Acid Orange II concentration, pH, and inorganic anion species on the degradation system were explored. BiOI/UiO-66(Zr) exhibited excellent visible light responsiveness. Under the optimal conditions (BiOI to UiO-66(Zr) mass ratio of 1 : 0.3, BiOI/UiO-66(Zr) dosage of 300 mg L−1, 0.3 mmol L−1 PMS, 100 mg L−1 Acid Orange II, 25 °C, and pH 7.0), the degradation efficiency reached 98.5%. While HCO3− and CO32− significantly influenced the reaction system, NO3−, Cl−, and SO42− had minimal impact. The reaction process followed a first-order kinetic model. Mechanistic analysis indicated that efficient transfer of holes and electrons between BiOI and UiO-66(Zr) occurred during the degradation, enhancing the separation efficiency of photo-generated electron–hole pairs. The ˙O2− and 1O2 generated in the reaction system played a crucial role in photocatalytic degradation of Acid Orange II, with ˙OH, SO4−˙, and h+ acting as auxiliary agents. The degradation process was a result of the synergistic action of various reactive radicals. Repetitive photocatalysis experiments demonstrated that the BiOI/UiO-66(Zr) composite exhibited excellent stability, with minimal reduction in degradation efficiency after four cycles. [ABSTRACT FROM AUTHOR]

A novel MOF-derived Mn2O3-decorated MoS2-graphene (MMG) composite was prepared via a facile hydrothermal method. The synthesized MMG composite was characterized through PXRD, FT-IR spectroscopy, DRS, TEM, FESEM, XPS and PL techniques. The prepared pure Mn2O3 exhibits a nano-chain-like agglomerated morphology with an average particle size of 50 nm distributed on the MoS2 and graphene layer as indicated by TEM images. DRS studies reveal a band gap of 1.22 eV for the MMG hybrid, demonstrating that the MMG hybrid can be used as a visible light–active photocatalyst. The study shows that the MMG-3 catalyst is excellent for the degradation of penicillin G under visible light with a rate constant (kapp) of 1.1 × 10−1 min. The photodegradation of PG by the MMG catalyst was found to be significantly faster than that by individual MSG or Mn2O3. The synergistic effect of MoS2 and graphene and a higher charge separation in the composite are major factors for a higher photocatalytic activity of the MMG catalyst. Moreover, the MMG catalyst exhibits good photostability, which ensures its potential applications in wastewater treatment and other energy applications. Finally, the photocatalytic mechanism of the MMG hybrid under visible light is presented after performing some radical scavenger tests. [ABSTRACT FROM AUTHOR]

Lignocellulose nanofibrils (LCNFs), as an emerging member of the green nanofibril family, have tremendous potential in improving the dispersibility, adsorption and photogenerated carrier separation efficiency of BiOBr because of the combination of the advantages of nanocellulose (NC) and nanolignins. Herein, sulfated lignocellulose nanofibrils (SLCNFs) were obtained from the poplar alkaline peroxide mechanical pulp (APMP) using a deep eutectic solvent (DES) and a mechanical defibrillation strategy, and flower-like BiOBr/SLCNF composites with oxygen vacancies were prepared by in situ synthesis. Due to the well-preserved lignin structure, abundant oxygen-containing functional groups, and the interconnected three-dimensional mesh structure in SLCNFs, the composites exhibited flower-like morphology, good dispersion and excellent adsorption performance after the introduction of SLCNFs. EPR analysis showed that the introduction of SLCNFs increased the number of oxygen vacancies in BiOBr, which improved the visible light absorption and reduced the recombination of photogenerated carriers. In addition, the photocatalytic activity improved with interfacial interaction between BiOBr and SLCNFs promoting the separation of electrons and holes. Therefore, BiOBr/SLCNF can effectively remove RhB in the dynamic continuous process of adsorption enrichment and photocatalytic oxidation. Under visible light, 99% of RhB was degraded within 30 min and 88.5% of tetracycline hydrochloride (TCH) was degraded within 60 min. Importantly, the main active species which removed RhB by BiOBr/SLCNF were ˙O2− and h+, and the BiOBr/SLCNF composites still have good stability and recyclability after 5 times of repeated use. Overall, the BiOBr/SLCNF composite photocatalyst has great potential for the purification of organic wastewater. [ABSTRACT FROM AUTHOR]

Pollution-related problems in the water environment caused by nuclear wastewater leakage has attracted widespread public attention. In this study, the strategy of treating waste with waste was adopted to prepare a tea waste-derived biochar/g-C3N4/MoS2 (BgM) Z-scheme composite for the photocatalytic reduction of U(VI) in water using thermal polymerization and hydrothermal methods. Among different proportions of BGMs, 10%BgM holds the highest removal efficiency of U(VI). Approximately all U(VI) was removed by 10%BgM under air atmosphere after 2 h of light irradiation (pH = 4.5, dosage is 0.5 g L−1). Furthermore, the removal efficiency of U(VI) by 10%BgM remained >80% after five cycles of tests, and it maintained a high selectivity in the presence of co-existing ions. Based on the quenching experiments and characterization analysis, photogenerated e− and ˙O2− play an important role in the reduction of U(VI). The enhancement of the photoreduction activity can be attributed to the acceleration of photogenerated electron transfer by the incorporation of tea waste biochar and the formation of a Z-type charge transfer mechanism, which improved the visible light absorption capacity. This study presents a promising material and approach for the effective treatment of uranium wastewater using photocatalysis. [ABSTRACT FROM AUTHOR]

The photocatalytic reduction of carbon dioxide into high value-added chemical feedstock is significant for mitigation of the energy crisis and the greenhouse effect. Metal–organic frameworks (MOFs) possess broad application prospects in photocatalytic CO2 conversion due to the ability to adjust the metal types in metal cluster nodes. Herein, the CO2 photocatalytic performance of trimetallic Fe0.02Ni0.10–Cox–PCN-250 (x = 0.05, 0.10, 0.15, 0.20 mol) was investigated by adjusting the content of Co. Notably, the photocatalytic yields of Fe0.02Ni0.10–Cox–PCN-250 (x = 0.05, 0.10, 0.15, 0.20 mol) were higher than those of bimetallic Fe0.02Ni0.10–PCN-250 and Fe0.02Co0.10–PCN-250 irradiated by visible light. The optimum yield of CO was obtained by trimetallic Fe0.02Ni0.10–Co0.15–PCN-250, up to 299 μmol g−1 h−1. The enhanced yield of CO might be ascribed to the high CO2 adsorption capacity and photogenerated electron transfer after addition of a suitable amount of the third ion, Co. This study provides new insights by designing trimetallic catalysts to increase the efficiency of photocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

The photodegradation of propranolol (PRO) by BiOCl0.5I0.5/persulfate under visible light was comprehensively investigated. The results demonstrated a significant increase in the removal efficiency of PRO under visible light irradiation, achieved by the combination of BiOCl0.5I0.5 solid solution and persulfate (PS). The photocatalytic activity of the system was found to be enhanced with an increase in the pH value. Additionally, the addition of a certain amount of PS improved the degradation of PRO. The presence of typical water constituents, Cl− and NO3−, had a negligible impact on PRO removal. In contrast, the increasing concentration of humic acid (HA) exhibited apparent inhibition of PRO degradation. Furthermore, radical scavenging experiments revealed that the removal of PRO was primarily facilitated by active free species, including h+ and ˙O2−. The presence of characteristic peaks of ˙OH (peak ratio 1 : 2 : 2 : 1), 1O2 and ˙SO4− in the EPR spectrum indicates that these three radicals are also involved in the degradation process. Moreover, the BiOCl0.5I0.5/PS system demonstrated excellent photocatalytic activity, as well as favorable reusability and stability. This study offers new insights into the photocatalytic degradation of PRO, presenting a promising approach in this field. [ABSTRACT FROM AUTHOR]

Heterojunctions are of great importance for improving photocatalytic performance. Using simple solvothermal and solid reduction techniques, plasmon bismuth (Bi0) nanoflake-decorated BiFeO3 (BBFO) heterojunction photocatalysts with numerous oxygen vacancies (OVs) were created. The OVs not only improved photo-generated carrier separation, but also the sorption and activation of antibiotic compounds (tetracycline hydrochloride, TC). Furthermore, the surface plasmon resonance (SPR) effect of the Bi0 nanoflakes can boost visible light absorption and inhibit charge carrier recombination, resulting in an excellent ability for TC elimination under visible light illumination. The removal ratio of TC for BBFO is up to 99%, which is several times higher than that for pure BiFeO3. The obvious photothermal effect could further enhance the photocatalytic activity owing to an SPR effect and defect engineering. Trapping experiments indicate that the emergence of plentiful OVs, the participation of metal Bi0 nanoflakes, and the formation of heterojunctions can significantly promote photogenerated charge separation, thus improving photothermal-photocatalytic performance. This work combines thermal and chemical energies in solar energy conversion for efficient degradation of pollutants, which would bring new ideas to solve the problems of environmental pollution and energy shortage. [ABSTRACT FROM AUTHOR]

Tetrabromobisphenol A (TBBPA), a prevalent brominated flame retardant, poses significant environmental and health risks, necessitating its removal. In this study, WO3 with different structures was synthesized for TBBPA photodegradation under visible light using H2O2 and O2 as oxidants. The catalyst exhibited robust stability and reusability, rendering it suitable for practical applications. The crystalline structure and surface structure of WO3 controlled its catalytic activity towards TBBPA photodegradation. Monoclinic WO3 with the (022) plane was found to be the most active for ˙O2− active species generation from H2O2 and thus active for TBBPA degradation. Degradation product analysis showed that the catalyst was active not only for the removal of TBBPA, but also for the debromination of TBBPA. Nearly 100% debromination was achieved. [ABSTRACT FROM AUTHOR]

Three-dimensional rose-like ZnO (R-ZnO) is an appealing photocatalyst due to its remarkable properties, while it is also essential to boost its current visible light photocatalytic performance. In this study, R-ZnO was prepared by the hydrothermal method, and oxygen vacancies and Ag nanoparticles were introduced by calcining the ZnO precursor in an argon atmosphere and the photoreduction method, respectively, to improve the photocatalytic activity. The prepared Ag/Ar-ZnO exhibits a narrower bandgap of 2.79 eV, highly increased light absorption both in the ultraviolet and visible light regions, and improved charge separation and transfer efficiencies induced by the relatively higher number of oxygen vacancies and the localized surface plasmon resonance (LSPR) effect of the Ag nanoparticles. Therefore, Ag/Ar-ZnO displays a significantly enhanced visible light photocatalytic performance, with a methyl orange (MO) photodegradation rate constant (Kap) that is 2.41 and 3.59 times higher than those of Ag-ZnO and Ar-ZnO, respectively. This research offers an effective way to enhance the photodegradation performance of R-ZnO under visible light irradiation. [ABSTRACT FROM AUTHOR]

The heterojunction structure of semiconductor photocatalysts is significant for making full use of their capabilities for organic molecules and dye degradation. In this paper, we present a heterogeneous junction composite fabricated with hybrid phase TiO2 and g-C3N4 for methylene blue (MB) removal through adsorption and photocatalytic degradation. The heterogeneous junction system was prepared by hydrothermal treatment with a subsequent pyrolysis process. The variation of the proportion and lattice structure of hybrid phase TiO2 in the synthesized catalysts was analyzed by refinement. Adsorption experiments showed that the maximum adsorption capacity of TiO2/g-C3N4 (1 : 10) was 1667 mg g−1, which was 45.97 times and 63.78 times higher than that of TiO2 and g-C3N4, respectively. In the photodegradation process, the TiO2/g-C3N4 (1 : 10) photocatalyst shows a removal rate of MB of 100 mg L−1, which was as high as 96.262%, significantly higher than that of pure TiO2 and g-C3N4. Brunner–Emmett–Teller (BET) measurements and Fourier transform infrared spectroscopy (FTIR) showed that the adsorption of MB onto TiO2/g-C3N4(1 : 10) was chemical adsorption, and ˙OH, which acts as an active substance, was found to play a major role in the photocatalytic degradation process. Overall, the developed hybrid phase TiO2/g-C3N4 heterojunction composite may be beneficial for the treatment of water pollution. [ABSTRACT FROM AUTHOR]

A novel metal-free and environment-friendly approach for synthesizing biologically important moieties, benzothiazoles and benzimidazoles, under visible light irradiation using photocatalyst Eosin Y, ethanol:water as a green solvent and atmospheric air as an oxidant has been developed. Using an organic dye, Eosin Y, provided a mild and economical catalytic system to synthesize a series of benzothiazoles and benzimidazoles in good to excellent yields. Besides, the photocatalytic system does not require an additional oxidant, which is good for the environment. This method has several advantages, including the absence of metals, low cost, environmental friendliness, green solvent, non-toxicity, ease of handling, and renewable energy sources such as visible light. [ABSTRACT FROM AUTHOR]

A new cobalt(II) coordination polymer 'Cp-Co' has been designed and synthesized. The construction includes cobalt(II) as the central metal core along with 1,4-benzenedicarboxylic acid and the spacer 3,5-diamino-1,2,4-triazole obtained by a solvothermal method. The architecture of 'Cp-Co' was established using single X-ray crystallography and the topology of the coordination polymer. The 'Cp-Co' exhibited a periodic 3D framework. Furthermore, infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) analysis further supported the structure of 'Cp-Co'. The prepared material was explored as a catalyst for the photocatalytic degradation of methyl green (MG) dye and displayed outstanding degradation efficiency under visible light radiation. The experimental design was explored towards optimization of the reaction variables, such as catalyst dose, MG dye concentration, etc. It was found that 10 mg of Cp-Co with 150 mg L−1 MG resulted in 99.77% photocatalytic efficiency within 60 min of visible light irradiation. The kinetic data was simulated using the Langmuir–Hinshelwood kinetic model and the value of the apparent rate constant (Kapp) was found to be 0.020 min−1, 0.024 min−1 and 0.029 min−1 for 50, 100 and 150 mg L−1 MG concentrations. The trapping experiments suggested the involvement of a superoxide anion radical (O2−˙) in the degradation of MG. [ABSTRACT FROM AUTHOR]

Herein, a pyridinium-based ionic liquid-functionalized porphyrin (PBILFPc) photocatalyst was successfully synthesized and characterized using various techniques, such as 1H NMR, HR-MS, FT-IR, SEM, and XPS. The surface area of the photocatalyst was calculated using the BET method and found to be 125.882 m2 g−1. The successful formation of the porphyrin was supported by the extremely shielded inner NH-protons at −2.61 δ ppm. The energy band gap and Hammett acidity were determined to be 1.42 eV and 0.64, respectively, using UV-Vis spectroscopy. Subsequently, PBILFPc was employed as a proficient photocatalyst for the arylation of various N-heterocycles with inactivated/activated aryl halides. The photocatalytic cross-coupling was achieved under metal/base/ligand-free conditions in a laboratory-made photoreactor under the exposure of 5 W white LED light and ambient conditions. Similarly, this protocol was also appropriate for a variety of N-heterocycles, offering N-substituted aryl/alkyl derivatives in appreciable yields (71% to 91%). The photocatalytic activity of PBILFPc was supported by its low energy band gap, promoting the absorption of radiation in the visible region and leading to the formation of excitons (holes and electrons). Moreover, the presence of Brønsted acidic groups together with excitons enhanced its photocatalytic activity at room temperature. This protocol afforded the synthesis of moieties analogous to clotrimazole using the optimized parameters. Furthermore, after the reaction, the reused PBILFPc photocatalyst was found to be active and afforded a reasonable yield (82%) even after six runs. Thus, this sustainable metal/base/ligand-free PBILFPc photocatalytic route in a homemade photoreactor under visible light will motivate investigators to study the synthesis of medicinally vital scaffolds and other intermediates. [ABSTRACT FROM AUTHOR]

The construction of heterojunction photocatalysts is an effective strategy to improve photocatalytic activity. Inspiringly, this is studied by the successful fabrication of new composites of a robust Zr-MOF and low-cost g-C3N4via a simple method of mechanical grinding followed by low-temperature heating. The synthesized composites exhibit characteristics of wide-range visible-light absorption, good long-term stability and significant photocatalytic hydrogen production. The optimal H2 production rate of the Zr-MOF/g-C3N4 (5.0 wt%) heterojunction was 1.252 mmol h−1 g−1, which was 41.7 and 15.7 times higher than that of pure Zr-MOF and g-C3N4, respectively. The Z-scheme charge transfer mechanism in Zr-MOF/g-C3N4 effectively improves charge separation and maintains its high redox ability, thus greatly enhancing photocatalytic hydrogen production activity. This study presents the rational fabrication of heterojunctions for photocatalytic applications and also provides new high-performance and low-cost MOF/g-C3N4 photocatalysts for H2 production. [ABSTRACT FROM AUTHOR]

The construction of photocatalysts with a Z-scheme heterojunction is considered to be a superior strategy for improving photocatalytic activity. In this study, a photocatalyst (PI/TiC/TiO2) with a Z-scheme heterojunction was fabricated, in which polyimide (PI) and TiO2 were used as the organic/inorganic semiconductor photocatalyst and TiC acted as the transmission bridge for electrons between PI and TiO2. In the self-made air flow photocatalytic reactor, the photocatalytic degradation efficiencies of organic dyes by PI/TiC/TiO2 increased with the increase of both the concentration and diffusion rate of O2. The degradation efficiencies of RhB and MB by PI/TiC/TiO2 reached 93.87% and 90.96%, respectively, within 90 min of visible light exposure, showing its outstanding photocatalytic performance. The mechanism analysis indicated that the Z-scheme heterojunction in PI/TiC/TiO2 facilitated the separation and migration of photoexcited charges while retaining stronger redox capabilities for charge carriers. This study provides an insight into the construction of visible light responsive organic/inorganic photocatalysts with Z-scheme heterojunctions for organic pollution treatment applications. [ABSTRACT FROM AUTHOR]

A novel light-driven non-enzymatic glucose sensor based on AuNi nanodendrites has been successfully constructed and applied in glucose detection. The AuNi nanodendrites were fabricated through a one-step underpotential electrodeposition approach, in which porous anodic aluminum was introduced as the template. This nanodendritic structure with a large surface area provides abundant active sites and good electron transfer for the oxidation of glucose. Considering the plasmonic effect of Au, such a hierarchical hybrid structure displayed remarkable photoelectrocatalytic activity for glucose under the visible light illumination. As a result, the light-driven glucose sensor based on AuNi nanodendrites reveals a high sensitivity of ∼183 μA cm−2 mM−1 (0.1–18 mM) and a relative low detection limit (0.01 mM), without applying an external electrical power supply. The current work is promising in the design of novel hybrid materials for glucose sensors under visible light illumination without electrical power consumption. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) is an important chemical widely used in the chemical industry. However, the current technical methods of producing H2O2 are limited by high cost, excessive energy consumption and environmental impact. Here, we construct Ti3C2 to modify K-doped g-C3N4 heterojunctions for the production of H2O2. Through the pretreatment of K-doped g-C3N4 and the electrostatic self-assembly method, Ti3C2 is closely bonded to effectively adjust the band position, resulting in a good synergistic effect and an excellent photogenerated electron transfer ability. The construction of this structure has improved the yield of H2O2 and the production of H2O2 under visible light illumination reached as high as 3401 μmol L−1, which is much higher than that of g-C3N4. In addition, the photocatalytic mechanism shows that the two-step single-electron reduction of O2 is the main reaction step of H2O2 production. The improvement of photocatalytic performance can be attributed to the doping of K and the construction of the heterojunction, which not only expands the absorption range of visible light, but also inhibits the recombination of photogenerated electron–hole pairs and accelerates carrier separation. At the same time, the catalyst has good stability and can be recycled. This work provides a deep understanding of the modification of g-C3N4 and a new strategy for the development of high-efficiency H2O2-producing photocatalysts. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) have great potential for producing photoelectrocatalyzed hydrogen and degrading pollutants, owing to several factors such as high porosity and tunable semiconductor-like properties. Wide band gaps, which restrict their use to only UV light induced reactions, and low efficiencies for the separation of photogenerated charge carriers (electrons and holes) pose significant challenges to the widespread applications of MOFs. In this study, a hierarchical hollow Pt@H-UiO-66-NH2/CdS ternary catalyst was designed and synthesized. The immobilized CdS nanoparticles (NPs) in this catalyst endow the MOF H-UiO-66-NH2 with high visible light absorption ability and the Pt NPs serve as electron sinks to improve charge carrier separation. Furthermore, the hierarchical hollow structure of H-UiO-66-NH2 in the composite contributes to boosting light absorption and shortening the distance for charge transfer. As a proof of principle, Pt@H-UiO-66-NH2/CdS catalyzes methylene blue (MB) degradation with a high rate constant of 1.025 × 10−2 and hydrogen production with a rate of 12 810 μmol g−1 h−1, the latter of which is about 2.3, 11.7 and 173 times higher than those of Pt@UiO-66-NH2/CdS, H-UiO-66-NH2/CdS and Pt@H-UiO-66-NH2, respectively. [ABSTRACT FROM AUTHOR]

Highly efficient 2D/2D layered heterostructure of nickel oxide (NiO) and molybdenum sulphide (MoS2) has been fabricated for the photoelectrochemical (PEC) water splitting and degradation of Bromophenol Blue (BPB) under visible light. The XRD spectra confirm mixed characteristic peaks of MoS2 and NiO in the nanocomposite. SEM displays flower-like patterns of pure and composite material with the 2D nanosheets layer structure. The band gap reduction (2.25–1.72 eV) is due to the incorporation of NiO in MoS2 for visible light harvesting. TEM confirms the homogeneous distribution of 2D/2D nanosheets. The excellent interfacial coupling in strong 2D/2D interactions boost the electro and photocatalytic activities. 15.0% NiO showed excellent PEC activity toward OER with maximum photocurrent density of 1.57 mA cm−2, which influenced the overall water splitting at lower potential, ensuring visible photoresponse. The maximum photodegradation performance for highly toxic BPB was achieved by the photocatalyst, which contains 15.0 wt% NiO in NiO/MoS2 composite. It displays the highest conversion efficiency (∼87.0%) for BPB owing to exposed active sites via Mo–Ni–S linkages. Defects in NiO/MoS2 offer favorable reaction dynamics to PEC OER, which are helpful in tuning the band potentials. [ABSTRACT FROM AUTHOR]

Building Z-scheme heterojunction systems is a high-efficiency pathway to improve the utilization of visible light. Herein, CsxPW11M/g-C3N4 (M = Co, Fe) was successfully prepared by the simple grinding and calcination technology with a Z-scheme heterojunction structure. This Z-scheme heterojunction structure could significantly improve the separation and utilization efficiency of photogenerated carriers while enhancing the redox capacity and photocatalytic activity. The energy band structure of Keggin-type polymers was optimized by modulating the coordination metal. The prepared composites have specific high photocatalytic properties and good reusability. The photocatalytic degradation activity of the prepared CsxPW11M (M = Co, Fe) modified 2D g-C3N4 materials was investigated using two different types of pollutants. Currently, when the loading capacity of CsxPW11M in the CsxPW11M/g-C3N4 sample reached 3 wt%, the photocatalyst of this composite material showed the best photocatalytic degradation performance. Meanwhile, the active species of the response were explored through free radical trapping experiments and ESR characterization, indicating that h+,˙O2 and ˙1O2 played a key role. The suitable band structure and the correct charge analysis, as well as the investigation of the transfer mechanism, provided new ideas for the construction of a Z-scheme heterojunction structure using Keggin-type transition metal-substituted heteropolymers and 2D g-C3N4. It improves the performance of conventional catalysts. [ABSTRACT FROM AUTHOR]

In the rapid growth of perovskite solar cells, there are still specific issues regarding the extensive absorption of incident photons. Double-layered methyl ammonium (MA)-free perovskite solar cells (PSC) have been proposed to sort out these issues. The material absorber in solar cells based on MA-free and cesium-based perovskite, i.e., Cs2BiAgI6, is a critical parameter because of its non-volatile nature as well as its band gap of 1.6 eV being helpful in a broader visible absorption spectrum than the conventional CH3NH3PbI3 material. Moreover, the quantum efficiency (QE) and power conversion efficiency (PCE) in a configuration with MXene + TiO2 as the electron transport layer (ETL) in the PSC can make improvements over a more extensive range. The results of the current modeling of numerical simulations are used to investigate the exclusive optoelectrical outputs of the PSC. Furthermore, we use a novel approach of an ETL of MXene + TiO2 in a PSC, which will lower the manufacturing cost and defectiveness. The present work compares different ETLs to attain the best PCE using Cs2BiAgI6 as a perovskite absorber layer (PAL). The results are exciting as the highest open circuit voltage (VOC) of 1.48 V, high short current density (JSC) of 22.8 mA cm-2, with a high fill factor (FF) of nearly 84.6% in the double-layered PSC offer a high power conversion efficiency (PCE) of more than 28%. The designed outputs will be efficient for the convenient fabrication of the PSC. [ABSTRACT FROM AUTHOR]

We employed a solvothermal and thermal pyrolysis approach to prepare a heterojunction of oxide perovskite (Bi2MoO6) dispersed on polymeric carbon nitride (PCN) sheets. The introduction of Bi2MoO6 particles onto the PCN sheets improved the light absorption characteristics of the Bi2MoO6/PCN heterojunction. The as synthesized Bi2MoO6/PCN heterojunction exhibited a larger surface area of 24 m² g-1, compared to the individual Bi2MoO6 (18 m² g-1) and PCN (7 m² g-1), respectively. This enhanced surface area provided newer catalytic sites for the heterojunction. The resulting heterojunction was employed as a photocatalyst for the reduction of a series of toxic mono, di, and tri-nitrophenols, namely 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, and 2,4,6-trinitrophenol, into industrially important amino phenols. By utilizing visible light irradiation and NaBH4 as a reducing agent, the Bi2MoO6/PCN photocatalyst demonstrated accelerated reduction kinetics compared to the individual catalysts. This enhanced performance was attributed to the larger surface area and suppressed charge carrier recombination of the Bi2MoO6/PCN heterojunction, which facilitated efficient photoreduction. Overall, this study sheds light on the promising application of oxide perovskite/PCN heterojunction systems in photocatalytic reduction reactions, offering a viable solution for mitigating emerging pollutants. [ABSTRACT FROM AUTHOR]

Molecularly imprinted Ni and F co-doped TiO2 nanoparticles were synthesized via the sol–gel method. The nanoparticles displayed high photocatalytic activity under both sunlight and artificial visible light for degradation of bisoprolol. Characterization of the nanoparticles was carried out using XRD, FE-SEM, TEM, FT-IR, DRS, EDX and BET-BJH. The effects of different operational variables on the photocatalytic activity were optimized using the response surface methodology (RSM). The optimal experimental conditions for achieving the highest photocatalytic efficiency (72.5% by a desirability function value of 1.0) are as follows: pH = 5.9, photocatalyst mass = 83.42 mg, bisoprolol concentration = 16.2 mg L−1, and irradiation time = 137 min. The selectivity of the photocatalyst was investigated against pantoprazole. The excellent photocatalytic activity is attributed to the doping of Ni and F dopants into the TiO2 structure. The investigation of the mechanism of the photocatalytic reaction revealed that the main active species involved in the degradation of bisoprolol are OH˙ radicals. [ABSTRACT FROM AUTHOR]

In this paper, a series of BN/NTCDA photocatalysts have been prepared using a simple calcination method and their photocatalytic performance under visible light irradiation is studied with tetracycline (TC) as the target pollutant. When the ratio of BN and NTCDA is 100 : 1 and the temperature is 350 °C, the sample (BN/NTCDA (100 : 1)) has the highest adsorption efficiency (28.65%) and photodegradation efficiency (51.54%) for TC. The characterization results of XRD, FTIR, XPS, TEM, and 1H NMR show that BN/NTCDA (100 : 1) is a BN-based photocatalytic material, which is likely formed through the reaction of the surface hydroxyl group of BN and the anhydride of NTCDA. The band gap of BN is about 4.11 eV, and the band gap of NTCDA is 2.67 eV. So, the electron is firstly excited from the VB of NTCDA to its CB, and then the electron in the VB of BN is excited into the empty VB of NTCDA, implying that TC is degraded by photoactive species (˙O2−, h+ and ˙OH) from the VB of BN and CB of NTCDA. The capture experiment of photoactive species suggests that ˙O2− makes the main contribution to TC photodegradation, followed by h+, ˙OH. After five recycle experiments, BN/NTCDA (100 : 1) still has 77.32% removal efficiency for TC. The removal efficiency (80.19%) of BN/NTCDA (100 : 1) is higher than that of TiO2 (75.63%) and g-C3N4 (24.44%). This work contributes to the development of novel metal-free-photocatalysts and the application of photocatalytic technology to the removal of antibiotics. [ABSTRACT FROM AUTHOR]

In this paper, Eu/F co-doped bismuth vanadate photocatalysts with different doping ratios were prepared by a hydrothermal method, and their microscopic morphology, crystal structure, light absorption and photocatalytic performance were investigated. Part of the F in the Eu/F co-doped samples might be doped to replace O in the BiVO4 lattice, while Eu3+ ions replaced Bi3+ ions, which led to a difference in the morphology and internal structure. XRD and Raman spectroscopy characterization showed that the crystal structures of the samples were all monoclinic scheelite type, and contained a certain tetragonal scheelite type, and the crystallinity was good. The Eu/F co-doped samples exhibited better photoactivity under UV-Vis light. The recombination rate of the photogenerated carriers in the Eu/F co-doped samples was obviously reduced, but it showed a serious concentration dependence on the doping species. Under visible light irradiation, Eu/F co-doped samples (R = 0.75) had the best degradation effect on methylene blue (MB). In addition, the degradation mechanism of the photocatalyst was also explored. ˙O2− and h+ were the main active species affecting the degradation of MB by Eu/F–BiVO4. [ABSTRACT FROM AUTHOR]

BiVO4, as a visible light catalyst, produces photogenerated electrons and photogenerated holes that are easy to recombine. In this paper, a BiVO4/Ag2O composite was prepared to promote the separation of photogenerated carriers of BiVO4. Compared with BiVO4, the properties and photocatalytic activity of BiVO4/Ag2O were obviously improved. The improvement of BiVO4/Ag2O was reflected in the better separation of photogenerated electrons and photogenerated holes, higher UV-visible maximum absorption wavelength, and stronger ability to degrade doxycycline. The effects of Ag2O on the crystal structure, the morphology and the binding energy of BiVO4 were analyzed by XRD, XPS and SEM, and the existence of a heterojunction in BiVO4/Ag2O was confirmed. The results of capture experiments showed that the photocatalytic processes of BiVO4 and BiVO4/Ag2O produced hydroxyl radicals (˙OH), holes (h+) and superoxide radicals (˙O2−). However, the contribution of active species was different in the two systems. The degradation pathways and intermediate products of doxycycline were analyzed by UPLC-QTOF. This work proposed a new method for the preparation of BiVO4/Ag2O particles with remarkable photocatalytic activity, and provided a reference for the degradation of doxycycline. [ABSTRACT FROM AUTHOR]

The development of high-efficiency photocatalytic materials responsive to visible light is one of the most effective ways to address the environmental threats posed by organic dyes in industrial wastewater. In this paper, novel visible-light-responsive nitrogen–sulfur co-doped carbon quantum dots modified ZnO (ZnO/N,S-CQDs) composites with a significantly enhanced photocatalytic degradation performance of Rhodamine B (RhB) were successfully synthesized. Under visible light, the photocatalytic degradation efficiency reached 98.7% over the optimal composite. Besides, the degradation obeyed the pseudo-first-order kinetics model with a photocatalytic rate constant (k) of 0.0473 min−1, which was around 3.71 times higher than that of pure ZnO nanoparticles (0.01273 min−1). In addition, the morphology, size and elemental composition of the ZnO/N,S-CQDs were characterized using TEM, SEM, XRD, FT-IR, and XPS which confirmed the successful synthesis of the composites. Photoluminescence (PL) and transient photocurrent response results indicated an increase in the carrier separation efficiency of ZnO/N,S-CQDs. Based on the active species removal experiment, superoxide radicals (˙O2−) played a leading role in the photocatalytic reactions and a possible photocatalytic degradation mechanism was revealed. These further demonstrate that the N,S-CQDs with varying properties contributed significantly to the enhanced photocatalytic activity of ZnO. Overall, the present method follows the principle of green economy, and novel N,S-CQDs provide a feasible approach for the development of photocatalytic performance of ZnO. [ABSTRACT FROM AUTHOR]

Antibacterial RBS@Cu:ZnO nanoparticles (NPs) were prepared by decorating Cu-doped ZnO NPs with Roussin's black salt (RBS), a nitric oxide (NO) precursor. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) tests indicated that the RBS@Cu:ZnO NPs were particulate matter with crystal morphology and nanoscaled sizes. X-ray diffraction (XRD) patterns revealed the wurtzite crystal structure of the NPs. Under irradiation of 543 nm laser, the RBS@Cu:ZnO NPs released NO in a controllable manner due to the decomposition of RBS. Cu-doped ZnO with a Cu/Zn molar ratio of 5% showed antibacterial activity in response to ultraviolet and visible light by photocatalysis. The doping of Cu enhanced the visible light absorption of ZnO by reducing its band gap. The RBS@Cu:ZnO NPs exhibited high antibacterial activity originating from the synergistic bacterial inhibitory effects of Cu-doped ZnO and released NO under visible laser irradiation. More importantly, the antibacterial activity could be controlled by adjusting the power output of laser irradiation. The RBS@Cu:ZnO NPs are promising antibacterial agents with potential applications in biomedicine and pharmaceutics. [ABSTRACT FROM AUTHOR]