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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]

In the present paper, polyaniline modification of Mn 0.5 Cd 0.5 S composite (PANI/MCS) was fabricated by a simple electrostatic adsorption method. The introduction of PANI makes PANI/MCS composites have better visible light absorption and higher photogenerated carrier segregation efficiency, thus showing better photocatalytic performance. The results show that the 50-PANI/MCS photocatalyst has the best hydrogen production capacity, which was 2.2 times greater than neat MCS. Meanwhile, the nitrogen fixation performance of the best sample 50-PANI/MCS was 4.93 times that of pure MCS. After that, a reasonable reaction mechanism was obtained through various characterization data. A cheap and readily available composite photocatalyst has been synthesized. This paper has good reference value in the area of development of efficient composite photocatalyst. In this paper, polyaniline modified Mn 0.5 Cd 0.5 S composite (PANI/MCS) was prepared by simple electrostatic adsorption. The introduction of PANI makes PANI/MCS composites have better visible light absorption capacity and higher photogenerated carrier separation efficiency, thus showing better photocatalytic performance. The results show that the 50-PANI/MCS photocatalyst has the best hydrogen production capacity, which is 2.2 times that of pure MCS. At the same time, the nitrogen fixation performance of the best sample 50-PANI/MCS was 4.93 times that of pure MCS. A cheap and readily available composite photocatalyst has been synthesized. [Display omitted] • A new method for the modification of Mn x Cd 1-x S by conductive polymer was proposed. • The whole prepared process of PANI/MCS composite material is cheap and simple. • PANI/MCS exhibits accelerated photogenerated carrier separation. • PANI/MCS exhibits better hydrogen evolution and nitrogen fixation performance. [ABSTRACT FROM AUTHOR]

The activation capacity of molecular oxygen is an important indicator to evaluate the photocatalytic efficiency of photocatalysts. In this paper, WS2 nanosheet was deposited on hyper-crosslinked CTF-1-G (obtained by molecular expansion from covalent triazine framework CTF-1) to form a C-GW heterojunction, which promoted the photodegradation of pollutants and the activation of molecular oxygen. This novel C-GW heterojunction exhibited excellent degradation property for organic pollutants (tetracycline (TC), rhodamine B (RhB)) and activating molecular oxygen under visible light irradiation. Among them, C-GW15 could degrade 98% of 20 ppm TC in 60 min and 99% of 30 ppm RhB in 30 min, and it had the highest hydrogen generation rate and hydrogen production amount in 4 hours, which were 8.74 mmol h−1 g−1 and 34.94 mmol g−1, respectively. Meanwhile, C-GW15 had the strongest 3,3′,5,5′-tetramethylbenzidine oxidation capacity and could generate 1.83 μmol of ˙O2− in 60 min and the production of H2O2 was 20.8 μmol L−1 in 40 min. The results of this study clearly indicated that the combination of WS2 and CTF-1-G can enhance the visible light absorption capacity and photogenerated carrier separation efficiency, thus promoting the photocatalytic performance. Finally, a Z-type photocatalytic mechanism was proposed based on radical capture, molecular oxygen activation experiments and electron spin resonance analysis. These findings will extend the fundamental understanding of the Z-type photocatalytic mechanism and provide new opportunities for the rational design of CTF heterojunctions for the treatment of environmental pollution and clean energy conversion. [ABSTRACT FROM AUTHOR]

In this paper, Co-doped MoS2 photocatalysts were prepared by hydrothermal method to achieve degradation of high concentration of rhodamine B under visible light. A series of characterization methods combined with photocatalytic properties and trapping agent tests were used to test and characterize MoS2 and CoxMo1–xS2 and found that the CoxMo1–xS2 crystal structure was consistent with MoS2 when the Co doping ratio was below 15%. Co doping causes MoS2 to form petal-like structures with more reactive sites; increases the visible light absorption intensity of MoS2 and reduces the forbidden bandwidth; and accelerates the migration of photogenerated carriers. Degradation experiments showed that the Co0.05Mo0.95S2 catalyst had the best photocatalytic effect with a decolorisation rate of 76.22% when doped with a 5% molar ratio of Co, and the photocatalytic effect was improved by 61% compared to pure MoS2. The capture agent tests demonstrate that the photocatalytic degradation process is h+ initiated and that the photocatalytic performance and chemical properties are stable after cycling tests. Based on density general function theory to construct a computational model of MoS2 and Co0.05Mo0.95S2, calculations using the first nature principle reveal that Co doping generates impurity energy levels in the MoS2 energy band structure, lowering the MoS2 band gap; disrupting the MoS2 charge distribution, forming a local potential difference in the semiconductor and promoting charge transfer. The reduced work function of the doped system enhances the ability of the photogenerated carriers inside the semiconductor to transfer to the surface, enhancing photocatalytic efficiency. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) is a clean and mild oxidant that is receiving increasing attention. The photocatalytic H2O2 production process utilizes solar energy as an energy source and H2O and O2 as material sources, making it a safe and sustainable process. However, the high recombination rate of photogenerated carriers and the low utilization of visible light limit the photocatalytic production of H2O2. S-scheme heterojunctions can significantly reduce the recombination rate of photogenerated electron–hole pairs and retain a high reduction and oxidation capacity due to the presence of an internal electric field. Therefore, it is necessary to develop S-scheme heterojunction photocatalysts with simple preparation methods and high performance. After a brief introduction of the basic principles and advantages of photocatalytic H2O2 production and S-scheme heterojunctions, this review focuses on the design and application of S-scheme heterojunction photocatalysts in photocatalytic H2O2 production. This paper concludes with a challenge and prospect of the application of S-scheme heterojunction photocatalysts in photocatalytic H2O2 production. [ABSTRACT FROM AUTHOR]

Water pollution caused by organic compounds, generated from different industries, has gained attention worldwide today. In this regard, significant efforts have been made for a suitable dye degradation technology. Zinc oxide (ZnO)–based photocatalysts are considered novel materials to degrade organic effluents in contaminated water. The facile synthesis of Ag/ZnO nanocomposites and its application for the enhanced degradation of indigo carmine (IC) dye under visible light irradiation is reported in this paper. The prepared photocatalysts were characterized using various analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron (XPS) spectroscopy, FTIR, Raman, impedance study, UV–Vis, and photoluminescence (PL). Prepared Ag/ZnO nanocomposites were tested for degradation of IC dye in visible light. The degradation efficiency of IC dye was found to be 95.71% in 120 min, with a rate constant of 0.02021 min−1. This improved photocatalytic activity of Ag/ZnO nanocomposites was mainly due to the absorption of visible light caused by surface plasmon resonance (SPR) derived from Ag nanoparticles (NPs) and electron–hole separation. Radical trapping experiments suggest that holes (h+) and superoxide radical (O2•–) are the key factors in photocatalytic IC dye degradation. [ABSTRACT FROM AUTHOR]

Copyright of Kemija u Industriji is the property of Croatian Society of Chemical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Increasing the active site of redox reactions on the surface of photocatalysts and accelerating the separation and transfer of photogenerated electron‐hole pairs are effective methods to improve the hydrogen evolution of composite photocatalysts. Non‐precious metal Ni photo‐deposition is anchored in situ on the ZnIn2S4 surface to generate the cocatalyst Ni(OH)2, which improves the photocatalytic hydrogen evolution performance of the composite sample. Under visible light irradiation, the ZnIn2S4 semiconductor stimulates photon‐generated carriers. Ni2+ acts as the defect center of photogenerated electron‐hole pairs to promote the separation of carriers. It serves as the capture site of light‐generated holes to reduce the carrier recombination rate so that the light‐generated electrons on the ZnIn2S4 surface promote H+ reduction in H2. Ni(OH)2 provides the active site for oxidation reaction on the surface of semiconductor materials, allowing the carrier to be consumed faster and improving the photocatalytic stability of semiconductor materials. The addition of 2 wt% Ni2+ resulted in a hydrogen evolution rate of 10 066 µmol·g−1 ·h−1 for ZnIn2S4/Ni(OH)2, which was 2.5 times higher than that of pure ZnIn2S4. This paper presents a reference case for enhancing the stability of sulfide to promote its photocatalytic hydrogen evolution. [ABSTRACT FROM AUTHOR]

The construction of bicyclo[1.1.1.]pentanes (BCPs) typically require the cumbersome use of labile [1.1.1.]propellane in solution and involve multicomponent radical reactions, which commonly produce undesired by‐products that hinder the efficient construction of BCPs. In this paper, we present a catalyst‐free strategy by constructing an electron donor‐acceptor (EDA) complex utilizing the naturally electron‐deficient nature of BCP thianthrenium salt, which were irradiated with visible light to obtain trifluoromethyl‐BCP radicals through a SET process, subsequently reacted with various substituted quinoxalines. Moreover, the successful structural modification of drug molecule derivatives confirm the utility of this scheme in the field of drug discovery. [ABSTRACT FROM AUTHOR]

In order to reduce the enormous costs of photocatalytic processes, the development of new photocatalysts sensitive to visible light constitutes a promising strategy to boost the efficiency of this method in water treatment. In this paper, strontium cobaltite nanoparticles (SrCo2O4 NPs) were shaped by simple, ecological and economical methods using cobalt and strontium nitrates as precursor and freshly isolated chicken egg white as capping agents. The crystalline product SrCo2O4 NPs was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Ultraviolet–Visible (UV–Vis) spectroscopy studies. The SrCo2O4-catalyzed Congo red (CR) degradation under visible light is investigated. XRD analysis showed that the sample was indeed crystallized in the cubic spinel structure (space group Fd3m). The average size of the nanoparticles was estimated to be ∼28nm. The FT-IR spectrum shows two bands at 620 and 573cm−1, which are characteristic of the spinel strontium cobaltite crystalline structure. The two optical band gap energy of synthesized photocatalyst estimated from UV–Visible spectrum is 2.07 and 3.48eV. The developed photocatalyst exhibits significant photocatalytic degradation of RC in an acidic medium with 97% of the dye mineralized after 5h. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) faces limitations in its photocatalytic applications due to its inherently wide bandgap (2.7 eV), low utilization of visible light, and a high rate of recombination of photogenerated electron–hole pairs. Defect engineering can effectively enhance the ability of g-C3N4 photocatalysts to address environmental pollution. In this paper, g-C3N4 materials with N defects (AA-CN15) were successfully prepared by using urea as a hydrogen bond donor and ammonium acetate as a hydrogen bond acceptor. The catalyst exhibits a broader range of visible light absorption, a lower rate of photogenerated electron–hole recombination, and a larger specific surface area, thanks to the formation of N defects in the N1 (C=N–C) vacancy. The formation of N defects reduces the band gap width of AA-CN15 from 2.85 eV to 1.90 eV compared to U-CN. The degradation rate of AA-CN15 in a 30 mg/L MB solution under visible light irradiation can reach 91.4% within 100 min, which is 7.2 times higher than that of U-CN. This study addresses the limitations and drawbacks of traditional defect introduction methods, offering a novel approach for the synthesis of N defect g-C3N4 materials. [ABSTRACT FROM AUTHOR]

NO has caused many serious environmental problems and even seriously threatened human health. The development of a cheap and efficient method to remove NO from the air has become an urgent need. In this paper, a novel nanocomposite metal-semiconductor photocatalyst Bi-Bi2Ti2O7/CaTiO3 was prepared. Compared to the original Bi2Ti2O7/CaTiO3, the modification by the metal Bi increased its photocatalytic activity from 25% to 64% under visible light irradiation. The improved photoactivity owns to the SPR effect and the electron capture effect of Bi metals in metal-semiconductor loaded systems improving the separation efficiency of electron-hole pairs and significantly improving the light absorption capacity of the composite photocatalyst. The capture experiment of active species showed that •OH, •O2−, h+ and e− are the main active species in the photocatalytic conversion of NO. This work provides new insights into the conformational relationships of Ti-based photocatalysts for NO removal. [ABSTRACT FROM AUTHOR]

In this paper, a series of corncob carbon modified g-C 3 N 4 composite catalyst with excellent visible light response properties was synthesized via a simple one-pot co-solvothermal method. The catalysts displayed enhanced adsorption performance and photocatalytic activity of 98.89 % and 99.08 % on Rhodamine B (RhB) and methyl orange (MO) removal efficiency under visible light irradiation, respectively. The superoxide radical and hydroxyl radical were the dominant reactive oxygen species involved in the photocatalysis reaction. The significantly enhanced adsorption and photocatalytic performance of the catalysts was ascribed to the porous structure and the strong interactions between g-C 3 N 4 and corncob carbon. After six cycles of experiments, the catalysts still exhibit stable and high performance for the removal efficiency of RhB and MO. Based on the analytical results, a possible mechanism of photocatalytic degradation was proposed in detail. The corncob carbon modified g-C 3 N 4 composites can be regarded as a potential catalyst in the application of the dye wastewater treatment. [ABSTRACT FROM AUTHOR]

In this paper, a MoSe2/TiO2 composite photocatalyst was constructed by modifying TiO2 with MoSe2 as a group catalyst. The results showed that pure TiO2 and MoSe2 had no degradation activity for RhB, and the composite catalyst of 0.03 g MoSe2 had the best photocatalytic degradation activity for RhB. Through SEM, TEM, UV-VIS absorption spectrum, transient photocurrent curve, photoluminescence spectrum, and electrochemical impedance spectrum analysis, it can be seen that the excellent performance of 0.03 g MoSe2 composite sample is due to its excellent nanostructure, and uniform TiO2 nanosheets are attached to MoSe2 flower spheres. The active site of RhB photocatalytic degradation was increased, the visible light response and photobiological carrier separation were enhanced, and TiO2 had photocatalytic activity under simulated sunlight. [ABSTRACT FROM AUTHOR]

Quantum dots (QDs) have been considered next-generation display fluorescent conversion materials due to their excellent color purity and photoluminescence quantum yield. In order to integrate QD with Micro/Mini-LED and other microdevices efficiently, it is necessary to fabricate micro-scale QD pixel arrays. Photolithography is an effective method for fine pattern processing, but conventional photolithographic procedures need to compound QD with a photosensitive curing matrix, which is not conducive to obtaining high color purity QD pixels. Therefore, a QD self-assembly strategy based on a hydrophobic-hydrophilic transformation substrate is proposed, combining ultraviolet (UV) mask exposure and surface charge modification technology to manufacture a high-purity QD pixel array. In this paper, the hydrophobic-hydrophilic transformation substrate is prepared by polyvinylidene fluoride (PVDF)/TiO2 hybrid fibrous membrane substrate. By changing the thickness of the substrate and analyzing its threshold of the photocatalysis time and pattern accuracy combined with the transmittance after encapsulation, the optimal substrate thickness is about 30 um. On this basis, the surface charge of the fibrous membrane is further modified by poly(diallyldimethylammonium chloride) (PDDA) to enhance the self-assembly performance of the QD in the hydrophilic region. The dimensional accuracy and optical characteristic of the QD pixel array have been studied in detail. The color average degree is 96.4%, the consistency is 94.5%, and the dimensional accuracy error is 5.2%. The spectrum of the QD pixel is almost the same as the QD solution, and the transmittance of the films is up to 88.8% under the visible light wave band, which has excellent optical performance. Therefore, this strategy is beneficial for efficiently manufacturing the high-purity QD pixel array, which has a broad application prospect in the high-resolution display field of Micro/Mini light-emitting diodes (LEDs). [ABSTRACT FROM AUTHOR]

In this paper, a novel S-scheme CuS/Bi5O7I heterojunction was successfully constructed using a two-step approach comprising the alkaline hydrothermal method and the adsorption–deposition method, and it consisted of Bi5O7I microrods with CuS particles covering the surface. The photocatalytic antibacterial effects on Escherichia coli (E. coli) were systematically examined with visible light exposure. The results suggested that the 3%-CuS/Bi5O7I composite showed the optimal antibacterial activity, completely inactivating E. coli (5 × 108 cfu/mL) in 180 min of irradiation. Moreover, the bacterial inactivation process was scientifically described. •O2− and h+ were the major active species for the inactivation of the bacteria. In the early stages, SOD and CAT initiated the protection system to avoid the oxidative destruction of the active species. Unfortunately, the antioxidant protection system was overwhelmed thereafter, which led to the destruction of the cell membrane, as evidenced by the microstructure changes in E. coli cells. Subsequently, the leakage of intracellular components including K+, proteins, and DNA resulted in the unavoidable death of E. coli. Due to the construction of the S-scheme heterojunction, the CuS/Bi5O7I composite displayed the boosted visible light harvesting, the high-efficiency separation of photogenerated electrons and holes, and a great redox capacity, contributing to an outstanding photocatalytic disinfection performance. This work offers a new opportunity for S-scheme Bi5O7I-based heterojunctions with potential application in water disinfection. [ABSTRACT FROM AUTHOR]

Photocatalysis has been regarded as a promising technology for degrading organic pollutants in wastewater and producing hydrogen. In this paper, TiO2 nanoparticles (NPs) were synthesized to improve the visible light absorption of TiO2, which were further combined with Bi2O3 nanosheets to synthesize a series of 0D/2D TiO2 NPs/Bi2O3 nanosheet heterojunctions. The visible light induced photocatalytic activities of the as-synthesized TiO2/Bi2O3 heterojunctions were studied. The optimized catalyst TB-3 with 15 wt% of Bi2O3/TiO2 exhibited the best photocatalytic degradation of tetracycline hydrochloride (TC). The degradation rate constant k of TC over TB-3 was approximately eight times and 39 times greater than that of P25 and Bi2O3, respectively. Additionally, TB-3 showed the highest amount of hydrogen evolution, while that of Bi2O3 was almost zero. The enhancement of photocatalytic performances was ascribed to the improved visible light absorption and the Z-scheme charge transfer path of the TiO2/Bi2O3 heterojunctions, which enhanced the separation efficiency and reduced recombination of photogenerated charge carries, as evidenced by UV–Visible diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), and electrochemistry measurements. The active species trapping experiments and the electron spin resonance (ESR) results revealed that ·O2− was the main active substance in the photocatalytic degradation. The possible degradation pathway and intermediate products of TC have been proposed. This work provides experimental evidence supporting the construction of Z-scheme heterojunctions to achieve excellent visible light induced photocatalytic activity. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Synthetic Crystals is the property of Journal of Synthetic Crystals Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Semiconductor‐based photocatalytic conversion of solar energy is a promising method for the synthesis of high value‐added chemicals. In this paper, a cocatalyst‐free nano‐twin crystal ZnxCd1−xS (T−ZnxCd1−xS) semiconductor was employed to achieve almost complete conversion of DNDPE and the yield of ODA product achieves >99 % in 40 min reaction time without additional hydrogen source. As far as we know, this is the first time to apply the photocatalytic technology for reducing DNDPE to ODA, and the photocatalytic efficiency has greatly exceeded the result of traditional catalytic method. Theoretical calculation and isotope labeling in situ HPLC‐MS analysis demonstrates that the reduction mechanism of DNDPE is two nitro groups of DNDPE are separately instead of simultaneously reduced, following the process of DNDPE→NO2−C6H4−O−C6H4−NO→NO2−C6H4−O−C6H4−NHOH→NO2−C6H4−O−C6H4−NH2→NO−C6H4−O−C6H4−NH2→NH2−C6H4−O−C6H4−NHOH→ODA. Hydrogen protons of water, instead of ethanol, provide the hydrogen source for the photocatalytic reduction of DNDPE to ODA. [ABSTRACT FROM AUTHOR]

In this paper, a series of Gd1-xBixFeO3 (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1) nanoparticles have been readily synthesized by a green and facile sol–gel method. It gradually changed from the orthorhombic structure (space group Pbnm) to the rhombohedral perovskite structure (space group R3c). Weak ferromagnetic behavior was effectively induced by Bi3+, with reduced magnetization. It was closely related with the lattice distortion of the perovskite structure and modified interactions between Fe-O-Fe. Boosted photocatalytic activities of Gd1-xBixFeO3 were observed for the removal of methylene blue (MB) under the visible light irradiation. In particular, Gd0.5Bi0.5FeO3 showed the optimum photocatalytic efficiency, in which the degradation efficiency reached 82.1% after 180 min of visible light illumination, with good stability and repeatability. The improved performance was mainly ascribed to enhanced visible light absorption, decreased optical band gap from 2.21 to 1.8eV and stronger charge transfer efficiency. A possible photocatalytic mechanism is also proposed according to the band structure. The results indicate that this system will be a promising candidate for the degradation of organic pollutant as a novel magnetically recoverable photocatalyst. [ABSTRACT FROM AUTHOR]

In this work, research articles dealing with the photocatalytic fixation of nitrogen using graphitic carbon nitride (g‐C3N4) were reviewed starting from 2015 when the first paper on this topic was published. The NH3/NH4+ production rates were adopted from these articles and statistically processed. The highest rate obtained by the composite g‐C3N4 and 1T‐MoS2 was 11120 μmol g−1 L−1 h−1. The highest reported rate provided by bulk (bare) g‐C3N4 was 5561 μmol g−1 L−1 h−1, which was higher than 90 % of the rates provided by the various composites of g‐C3N4. The quantum efficiency of the composites varied from 0.033 to 5.65 % with a median of 1.25 %. Although these results are still not competitive with the industrial Haber‐Bosh process, graphitic carbon nitride is recommended as a promising material for the future investigation of photocatalytic nitrogen fixation under visible light. [ABSTRACT FROM AUTHOR]

The paper deals with the synthesis of a binary ZnO/Ph-g-C3N4 nanocomposite, a highly efficient visible light active catalyst for the photodegradation of organic pollutants in aqueous suspension by single-step calcination and combustion process. The synthesised materials have been characterised using different techniques such as X-ray diffraction, UV-Vis, FTIR, SEM-EDX, and TEM. The UV-Vis DRS analysis indicates 20–30 nm red-shift and a decrease in bandgap from 3.1 to 2.7 eV on doping ZnO with Ph-g-C3N4. The photocatalytic activity of the prepared nanocomposites was tested by studying the degradation of two different chromophoric dyes, rhodamine B (RhB) and methyl orange (MO) and a drug derivative, Paracetamol. The composite, 0.05% ZnO/Ph-g-C3N4, displayed the best activity for the degradation of both dyes and the drug. The trapping and quenching studies indicate that both hydroxyl and superoxide radical anions are responsible for the degradation of pollutants under investigation. The higher photocatalytic activity of the prepared samples could be attributed to the generation of heterojunction between the Ph-g-C3N4 and ZnO, which is the response for improved light absorption and efficient separation of the photo-excited electron and hole pair. [ABSTRACT FROM AUTHOR]

In this paper, Mn 0.5 Cd 0.5 S (MCS) was prepared by hydrothermal method and CoB was introduced as a co-catalyst for the synthesis of CoB/Mn 0.5 Cd 0.5 S (CBMCS). After the characterization of UV–vis DRS, PL, photocurrent, EIS, LSV and Mott-Schottky, it is proved that the introduction of CoB plays a prominent role in inhibiting the photogenerated charge recombination and boosting the responsiveness to visible light. The photocatalytic hydrogen precipitation experiments revealed that the hydrogen evolution rate of CBMCS composite was up to 3810.0 μmol h−1 g−1, which was 7.0 times higher than MCS with a hydrogen precipitation rate of 543.3 μmol h−1 g−1, and 2.2 times higher than 1%Pt/MCS with a hydrogen evolution rate of 1729.1 μmol h−1 g−1 and kept excellent stability. Then by theoretical calculation and UPS, the work function was obtained to prove the formation of the Schottky junction between MCS and CoB. Obviously, this study provides a low-cost and effective co-catalyst to replace the precious metal Pt, offering a doable scheme to boost the photocatalytic activity of Mn 0.5 Cd 0.5 S. [Display omitted] • CoB/Mn 0.5 Cd 0.5 S (CBMCS) photocatalyst with schottky junction was successfully prepared. • CBMCS photocatalyst exhibits excellent performance for splitting water to H 2. • An inexpensive and effective cocatalyst replaced Pt was shown. • The possible mechanism of CBMCS photocatalytic materials is proposed. [ABSTRACT FROM AUTHOR]

In this paper, a facile one step synthesis method for the preparation of C-, B-, P- and S-doped g-C 3 N 4 by incorporation of small concentration of doping element precursor into urea during thermal polycondensation is reported leading to much lower doping levels than the ones usually reported. The as-obtained doped g-C 3 N 4 photocatalytic materials are deeply characterized in terms of structural, morphological, surface and optical properties. Doping yields beneficial surface morphology modulation along with improved optical, electronic and photocatalytic properties. In particular, C-doped and S-doped g-C 3 N 4 show, after deposition of gold nanoparticles (<1 wt%), enhanced photocatalytic performance (at least twice as high as the undoped photocatalyst, to achieve ca. 610 μmol/h/g) for the production of H 2 by water splitting under solar light in the presence of low content (1 vol%) of triethanolamine (TEOA) as sacrificial agent. The most remarkable activity results from the incorporation of traces of S dopant, mainly inserted into interplanar hollow cavities. The enhanced activity is attributed to a combination of high surface area, location of the S dopant and small size of the co-catalyst NPs, which induces enhanced visible light harvesting, enhanced charge carrier separation and enhanced proton recombination. This work highlights the benefits of the optimized low-level doping strategy to overcome the main limitations of g–C 3 N 4 –based photocatalysts. [Display omitted] • H 2 production by water splitting with non-metal doped g-C 3 N 4 using low amount (1 vol%)TEOA. • Enhanced H2 production rate induced by trace level (<0.1 wt%) of S-dopant. • Benefits of low-level doping strategy to overcome the main limitations of g-C 3 N 4. • One-pot easy synthesis of non-metal doping of g-C 3 N 4 during thermal polycondensation. • Those photocatalyst exhibit enhanced visible light harvesting properties. [ABSTRACT FROM AUTHOR]

Developing a hybrid process for wastewater purification is of utmost importance to make conventional methods more efficient and faster. Herein, an effective visible light-active nickel–nickel oxide/carbon/graphitic carbon nitride (Ni-NiO/C/g-C3N4)-based nanocatalyst was developed. A hybrid process based on ozonation and Ni-NiO/C/g-C3N4 visible light photocatalysis was applied to decolourize the Congo red (CR), Alizarin Red S (ARS), and real dairy industry wastewater. The synthesized catalyst was characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Χ-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectrophotometry (UV-Vis DRS). The factors affecting the catalytic process were evaluated, including contact time, solution pH, initial dye concentration, etc. The degradation rate of CR and ARS was compared between the photocatalysis, ozonation, and integrated photocatalytic ozonation (PC/O3) methods. The results showed 100% degradation of CR and ARS within 5 min and 40 min, respectively, by integrated PC/O3. The reusability of the modified catalyst was evaluated, and four successive regenerations were achieved. The modified Ni-NiO/C/g-C3N4 composite could be considered an effective, fast, and reusable catalyst in an integrated PC/O3 process for the complete decolourization of wastewater. [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]

Novel two-dimensional (2D) oxides are of great interest for photocatalysis because of their superlative physical features, namely, large surface areas, short charge diffusion pathways, high crystallinity and easy surface modification. However, most 2D oxides suffer from weak visible light absorption and severe photogenerated carrier recombination. Nitrogen doping can successfully narrow the bandgap of 2D oxides but can hardly improve the charge separation. In this work, we pre-dope nitrogen into 2D titanate nanosheets (HTiO), followed by surface processing with solution plasma. By dual modification of nitrogen doping and solution plasma processing (SPP), the modified 2D titanate nanosheets (N-HTiO-SPP) display broad absorption extending to the visible light region and the healing of oxygen vacancies brought about by nitrogen doping. Compared with HTiO and nitrogen doped titanate (N-HTiO), a higher removal rate and mineralization rate towards the photocatalytic degradation of acetaldehyde were achieved over N-HTiO-SPP under solar light. This work provides a powerful way to activate 2D wide bandgap semiconductors for enhanced photocatalytic activity. [ABSTRACT FROM AUTHOR]

As an interesting photocatalytic material, black TiO2 has high research and application value. Some desirable adsorption and photocatalytic composites will be fabricated in combination black TiO2 with montmorillonite (MMT). In this paper, nano-structures of TiO2/MMTs were characterized by XRD, FT-IR, Raman, XPS, PL and UV–Vis DRS. It can be concluded that the existence of MMT delays the crystal transformation of TiO2. New Ti–O–Si bonds, oxygen vacancy clustering and minimal Ti (III) contents were emerged and intensified in black TiO2/MMT. These special structures are helpful to preventing the recombination of electrons and holes which were used to degrade the dye molecules. The photocatalytic performance was determined by the decolorization ratio of two kinds of dyes under sunlight or indoor visible light. The degradation efficiencies of rhodamine B (Rh B) and methyl orange (MO) can reach 78.7% and 53.2%, respectively, after illuminated for 140 min under sunlight. The assessment of radical scavengers shows that the main functional radicals in the degradation of Rh B and MO were ·O2− and ·OH, respectively. These new catalysts have wide range of utilization in the degradation of phenols, aromatics, pesticides and antibiotics compounds. [ABSTRACT FROM AUTHOR]

Pyrazinoquinoxaline-based graphdiyne (PQ-GDY) contains a fixed number of sp−sp2 hybridized carbon atoms and pyrazine-like sp2 hybridized N atoms. In this paper, NH 2 -UIO-66(Zr) on PQ-GDY substrate was successfully constructed with the help of microwave-assisted heating. PQ-GDY surface acts as a microwave antenna under microwave irradiation to rapidly absorb microwave energy and form hot spots (hot spot effect), which facilitates the formation of well-dispersed NH 2 -UIO-66(Zr) with good crystallinity. Transient absorption spectra show that high hole transport property of PQ-GDY can accelerate the migration of photogenerated holes from NH 2 -UIO-66(Zr) to PQ-GDY and greatly reduce the recombination rate of photogenerated electrons and holes due to the strong interaction between PQ-GDY and NH 2 -UIO-66(Zr). Under visible light (λ ≥ 420 nm), PQ-GDY@NH 2 -UIO-66(Zr) shows high photocatalytic stability and high NO x removal rate up to 74%, which is 44% higher than that of primitive NH 2 -UIO-66(Zr). At the same time, it inhibits the formation of toxic by-products (NO 2) and limits its concentration to a low level. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, WS2/Zn0.5Cd0.5S sheet-like nano-heterostructure photocatalysts were prepared by coprecipitation-hydrothermal method. The composition of the materials was characterized by XRD, and the morphology and size of the photocatalysts were observed by SEM and TEM. The absorption band edge, photo-generated carrier recombination efficiency and interface electron transfer rate of the composite were studied by UV–Vis DRS, PL and EIS methods. The degradation experiments showed that the decolorization rate of 9%-WS2/Zn0.5Cd0.5S composites to methylene blue (MB)reached 92.6% at 240 min. The photocatalytic degradation activity of WS2/Zn0.5Cd0.5S is higher than that of WS2 and Zn0.5Cd0.5S. The photocatalytic mechanism of MB degradation by WS2/Zn0.5Cd0.5S was revealed based on energy band position, PL analysis and trapping agent analysis. In addition, the photocatalyst not only has good photocatalytic performance, but also has good stability. [ABSTRACT FROM AUTHOR]

In order to find a green and effective chemical desulfurization method, the photocatalytic technology and oxidative desulfurization were combined to minimize the sulfur content in coals. In this paper, 30% H2O2 was mixed with raw coal, demineralized coal, and removal pyrite coal at a ratio of 5:1 (ml: g), the oxidative desulfurization reaction was carried out with visible light irradiation for different times, and compared with the experimental results without light irradiation under the same condition. IC was used to characterize the SO42- content in the filtrate of the reaction mixture, and the chemical method was used to determine the forms of sulfur in coal samples before and after desulfurization, FTIR was used to characterize the change of sulfur-containing functional group content in coal samples before and after desulfurization. And the photochemical characterization of raw coal, demineralized coal and removal pyrite coal were carried out to explore the photochemical properties of different coal samples, further explored the reasons for the promoting effect of visible light irradiation on H2O2 oxidation desulfurization. The experimental results showed that the desulfurization efficiency can be significantly enhanced by visible light irradiation. Under the optimum conditions, the desulfurization rate can reach 67.68%, most of the pyrite and part of organic sulfur in coals were effectively removed. The pyrite in coal was the main reason for the promotion of H2O2 oxidative desulfurization by visible light irradiation. [ABSTRACT FROM AUTHOR]

The practical fabrication of quantum dot materials, including their size, shape, form, crystallinity, and chemical composition, is a crucial research area in the field of photocatalysis. Quantum dots can effectively enhance the separation and transfer of carriers and expand the utilization of visible light when used in heterogeneous junctions with wide bandgap semiconductors. Additionally, they exhibit excellent photosensitivity properties that significantly improve the material's capacity for absorbing visible light. This paper systematically presents an overview of the outstanding optical properties exhibited by quantum dots based on both domestic and international research on photocatalytic materials. Furthermore, it summarizes the research content, characteristics, and current challenges associated with common types of quantum dots and photocatalytic materials while highlighting their applications in environmental remediation and energy production. Finally, this paper anticipates future trends in the development of photocatalysis by providing valuable insights into more efficient semiconductor materials that are cost-effective yet environmentally friendly. [Display omitted] • The types, properties and application prospects of quantum dots in various fields are reviewed. • It gives the descriptive function of various quantum dot modified photocatalysts and how their photocatalysis is affected. • It further emphasizes the application of quantum dot composites in the fields of photocatalytic CO2 reduction, hydrogen evolution and degradation. [ABSTRACT FROM AUTHOR]

Due to the semi-closed structure of the tunnel, serious air pollution in tunnels from vehicle exhaust becomes an issue which needed to be addressed. Among the exhaust, nitric oxide (NO) is typically considered as one of the main pollutants. In this paper, a superhydrophobic photocatalytic coating was fabricated by a spraying method by airbrush with a WO3/TiO2 photocatalysis for NO degradation. The water advanced contact angle (WACA) of the coating reached 166.32°, and the WACA was still above 145° after the 30 times abrasion test. The coating exhibited an excellent ability to remove inorganic and organic pollutants. Also, the NO degradation efficiency of this superhydrophobic coating under ultraviolet and visible light sources and humid environments was tested. When the relative humidity reached 98%, the NO degradation efficiency of the coating remained unchanged under visible light irradiation compared with the relative humidity of 45%. In addition, the coating exhibited prominent stability of NO degradation during the cyclic test. Furthermore, the WT coating showed stability and synergy of self-cleaning and photocatalysis toward NO degradation, which ensured the long-term use of the coating. Finally, a synergistic mechanism for self-cleaning and photocatalysis was proposed. This may provide a new idea and support for the application of photocatalytic technology in the degradation of NO in the tunnel. [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]

Semiconductor heterojunction have received wide attention for their enhanced catalytic properties. In this paper, the PZT/CdS pyroelectric heterojunction prepared by hydrothermal method has remarkable pyro-/photo catalytic degradation performance and RhB can be almost completely degraded within 120 min. The pyro-/photo catalytic degradation of RhB by PZT/CdS was 99.25% under 20–55 °C and visible light irradiation, which was 1.5 times and 6 times that of PZT/CdS (64.72%) and PZT (16.35%) photocatalysis, respectively. The increase of decomposition rate is because the introduction of CdS not only expands the light response range of the material, but also improves the redox ability of the material. At the same time, CdS and PZT can also produce pyroelectric effect under temperature fluctuation. Double pyroelectric effect and heterojunction work together to further promote the separation of carriers. This study confirmed that PZT/CdS heterojunctions based on pyroelectric effect can achieve efficient pyro-/photo catalysis by using solar/thermal energy, which provides a reference in the field of catalytic degradation of dye wastewater by multiple energy sources. [ABSTRACT FROM AUTHOR]

CO2, a major contributor for global warming may be considered as a free source of carbon and can be converted into hydrocarbons. Mimicking the photosynthesis process that utilizes light energy to convert CO2, is the favorable option, and solar energy may be harnessed. The present paper reports the visible light mediated photocatalytic reduction of CO2 to formic acid, formaldehyde and methanol using Polyaniline-TiO2 nanocomposites (PANI-TiO2) in aqueous media under ambient conditions. The optimum TiO2 content in the nanocomposite to maximize the yield of formaldehyde and formic acid is 18.2% by weight, and it has a band gap of 2.81 eV. The yield of formaldehyde, formic acid and methanol obtained were 80.57, 32.17 and 6.3 μmole/g catalyst, respectively, in eight hours with 0.3 g/L catalyst loading. The catalyst loading of 0.7 g/L is the optimum loading to maximize the yield of formaldehyde and formic acid. Maximum yield of methanol was obtained with PANI-TiO2 containing 35% TiO2. This approach can lead the energy sector toward a non-fossil fuel-based economy. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) is a metal-free photocatalyst with visible light response. However, the disadvantages limit its application in a wider range, such as its small specific surface areas, fewer active sites, narrow visible light absorption range and high photogenic carrier recombination. In this paper, NaOH was used as an activator for alkaline activation of g-C3N4. The phase composition, micromorphology, surface chemical state and optical properties of g-C3N4 after activation were tested. The photocatalytic performance of g-C3N4 over organic dyes was also tested. The results showed that Na+ entered the interlayers of g-C3N4, expanding the spaces between layers. The specific surface area and pore volume of powder were increased. The active sites were increased. The band gap was decreased, and the photogenic carrier recombination was reduced. Alkaline activated g-C3N4 had better adsorption and degradation performance over rhodamine B and methyl orange than inactivated g-C3N4. Therefore, the alkaline activated g-C3N4 promotes its further application in the field of wastewater treatment. This work sheds light on the material modification through a simple method with the aim to efficiently use solar energy. [ABSTRACT FROM AUTHOR]

In this paper, Z-scheme Bi2MoO6/CNTs/g-C3N4 composite photocatalysts were prepared through a simple hydrothermal method. The analysis was performed by XRD, FT-IR, SEM, EDS, TEM, HRTEM, XPS, BET, UVâ€"Vis diffuse reflectance and PL spectrums. Various analyses show that CNTs not only act as excellent charge transfer bridges, but also enable a formation of the Z-scheme of charge transfer mechanism between Bi2MoO6 and g-C3N4. This process not only effectively isolates electrons and holes, but also prolongs electronâ€"hole pair lifetimes, resulting in a substantial improvement in the photocatalytic performance of the composite photocatalyst. Best photocatalytic degradation performance was shown by Bi2MoO6/CNTs/g-C3N4 composite photocatalyst under simulated sunlight, while the composite photocatalyst still maintained extremely high degradation performance in cycling tests. [ABSTRACT FROM AUTHOR]

Titanium oxide nanoparticles (TiO 2 NPs) are a semiconductor material widely employed as photocatalysts for environmental remediation owing to its excellent properties. Nevertheless, collecting the nanomaterial once dispersed in the aqueous media is challenging, while the photocatalytic activity is limited mainly to the ultraviolet range of radiation. In this work, we have modified cellulose paper, a sustainable and green support, with a polymer nanocomposite comprising nylon-6 and different nanomaterials, i.e., anatase TiO 2 nanoparticles (NPs) as well as TiO 2 decorated with Ag and Au in form of NPs by means of a simple procedure. The immobilization of the nanocomposite on paper mediated the subsequent recovery of the substrate upon incubation. The presence of nylon-6 enables both the attachment of the NPs on the support as well as the isolation of the pollutant from the contaminated water due to the interactions with the target analyte, i.e., methyl orange (MO). Additionally, the presence of the mentioned polyamide within the substrate triggers the photocatalytic reaction under visible light radiation. The broadening in the range of the light towards the use of sunlight has been also evaluated via modification of the photocatalyst nanoparticles with noble metals such as silver and gold. The kinetic of degradation of MO upon sunlight exposure with the different polymeric nanocomposites followed a pseudo-first-order model, with k constant values of 0.070, 0.083 and 0.120 min−1 for TiO 2 , Ag@TiO 2 and Au@TiO 2 nanocomposites, respectively. The effect of the presence of the polymer on the substrate has been evaluated, observing an increase in the k constant upon addition of the polyamide from 0.036 to 0.069 min−1 for TiO 2. The synergistic effect of sorption/degradation enables the regeneration of the substrates modified with the nanomaterials that can be reused several times, the relative standard deviation of k upon three subsequent photocatalytic cycles being in the range 15.7–37.7%. [Display omitted] • Cellulose paper has been modified with nylon-6 and TiO 2 nanocomposites. • Nanocomposites of TiO 2 modified with Ag and Au nanoparticles have been synthesized. • Photocatalytic properties have been evaluated for the degradation of methyl orange. • Nylon-6 triggers photocatalysis under sunlight and improves degradation rate. • Self-cleaning of the paper nanocomposites enables several cycles of photocatalysis. [ABSTRACT FROM AUTHOR]

In this paper, Zn 2 SnO 4 /SnO 2 /g-C 3 N 4 ternary composite catalysts were synthesized using hydrothermal and calcination methods to degrade rhodamine B aqueous solution under simulated sunlight. [Display omitted] • A ternary composite photocatalyst with heterojunction structure was constructed. • The heterojunction has an ultra-high degradation rate of 99.5% in RhB degradation. • The heterojunction has excellent stability and reusability properties. • The degradation mechanism of Rhodamine B over Zn 2 SnO 4 /SnO 2 /g-C 3 N 4 has been revealed. Photocatalysis is an effective solution to wastewater treatment problems, and semiconductor heterojunctions for photocatalysis can effectively separate photogenerated carriers to improve the performance of photocatalytic degradation of pollutants. In this paper, a ternary composite photocatalyst with a heterojunction structure (Zn 2 SnO 4 /SnO 2 /g-C 3 N 4) was prepared to photodegrade Rhodamine B in simulated visible light. The experimental findings demonstrate that the Zn 2 SnO 4 /SnO 2 /g-C 3 N 4 photodegradation rates and efficiencies for RhB are much higher than those for SnO 2 , g-C 3 N 4 , SnO 2 /g-C 3 N 4 , and Zn 2 SnO 4 /SnO 2. We obtained a 3:1 mass ratio of Zn 2 SnO 4 /SnO 2 to g-C 3 N 4 by optimization, with a maximum degradation rate of 99.5 % and a maximum kinetic constant k of 0.692 min-1·g−1 for the photocatalytic removal of RhB by Zn 2 SnO 4 /SnO 2 /g-C 3 N 4. The radical trapping experiments suggest the primary role of ·O 2 – for the photocatalytic removal of RhB. The ternary composite photocatalyst Zn 2 SnO 4 /SnO 2 /g-C 3 N 4 shows promise for potential applications in RhB degradation owing to its exceptionally. [ABSTRACT FROM AUTHOR]

In this paper, a simple one-pot thermal synthesis method was used to successfully prepare Cu2+/biochar-doped TiO2 composite catalytic materials. The photocatalytic hydrogen production performance of the composites under different environmental conditions (dark, solar, and visible light irradiation) was analyzed in a biomass photocatalytic system using a corn straw suspension as a sacrificial agent. The Cu2+/biochar-doped TiO2 materials were characterized by SEM, TEM, XRD, FT-IR, XPS, and UV analysis. The photoelectric properties of the Cu2+/biochar-doped TiO2 composites were also analyzed, and the charge separation mechanism of photogenerated carriers under different environmental conditions was investigated. Compared with pure TiO2, the hydrogen production rate of Cu2+/biochar-doped TiO2 is 23.6 times higher under visible light irradiation and 16.8 times higher under simulated solar irradiation. Using density functional theory, a crystal structure model of Cu2+/biochar-doped TiO2 was established to analyze its energy band structure and density of states. An analysis of the mechanism shows that under simulated sunlight irradiation, the synergistic effect of the TiO2 doped with Cu2+ and biochar causes the formation of a potential Schottky heterojunction on the surface and induces interfacial charge transfer. Furthermore, under visible light irradiation, the photocatalytic production of hydrogen by the Cu2+/biochar-doped TiO2 composite is mainly due to the surface plasmon resonance mechanism of Cu ion-doped TiO2. [ABSTRACT FROM AUTHOR]

Photocatalytic technology provides a new strategy for mitigating energy crisis. The development of photocatalytic materials with high efficiency and stable visible light response has always been the direction of researchers in the field of photocatalysis. Graphite carbon nitride (g-CN) has attracted ever increasing attention in the field of photocatalysis due to its special characteristics (such as visible light response, high stability, and low cost). However, the low separation efficiency of photogenerated electrons and holes limits its catalytic activity. In this paper, a novel g-CN-based intramolecular donor–acceptor (D–A) system was prepared to promote the separation efficiency of light-induced charge carriers. The catalyst is prepared from g-CN and 1,2-dibromobenzene (Bz) through a simple calcination method. Characterization results confirmed that Bz was successfully introduced into the g-CN (g-CN-Bz (x)) framework. The formation of the D–A structure leads to the spatial separation of electrons and holes pairs, which significantly accelerates the separation efficiency of charge carriers. Moreover, the D–A structure plays an important role in adjusting the width of band gap, which can increase the light absorption capacity of the catalyst. The D–A system also leads to the formation of a built-in electric field, which significantly accelerates the migration speed of electrons. Among the prepared catalysts, g-CN-Bz (0.01) has the best photocatalytic CO2 reduction performance, and the evolution rate of CO is 5.2 times higher than that of CN (3.64 μmol g−1). In addition, the reaction is carried out in water without any sacrificial agent, which makes it green and environmentally friendly. The charge carrier excitation-recombination process between donor and acceptor, and photocatalytic reduction of CO2 to CO over the CN based DA composites. [ABSTRACT FROM AUTHOR]

Reduction-and-oxidation (redox) reactions are one of the most utilized approaches for the synthesis of value-added compounds. With the growing awareness of green chemistry, researchers have searched for new and sustainable pathways for performing redox reactions. From this, a new field has gained tremendous attention, namely photoredox catalysis. Here, molecules can be easily oxidized or reduced with the use of one of Nature's biggest resources: visible light. This tutorial paper gives the basics of photoredox catalysis along with limited examples to encourage further research in this blooming research area. 1 Introduction 2 Redox Chemistry 3 Photochemistry 3.1 Laws of Photochemistry 3.2 Principles 3.3 Examples 4 Photoredox Catalysis 4.1 General Principles 4.2 Classification of Redox Processes 4.3 Other Mechanistic Considerations 4.4 Stern–Volmer Plots 4.5 Photophysical Properties 4.6 Redox Potentials 5 Photocatalysts 5.1 Metal-Based Photocatalysts 5.2 Organic Dyes 5.3 Semiconductors 6 Dual Catalysis 7 Conclusions [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to improve the degradation efficiency of Rhodamine B (RhB) by new photocatalytic materials. Design/methodology/approach: Binary Z-scheme g-C3N4/Bi2WO6 photocatalytic material was synthesized by the one-step hydrothermal reaction. The construction of Z-scheme heterojunction led to the rapid separation of photogenerated electrons and holes, which would degrade RhB into small molecular substances to achieve the purpose of degradation. Findings: It was found that Bi2WO6/25%g-C3N4 displayed the highest photocatalytic activity, which was about 1.44 and 1.34 times higher than that of pure Bi2WO6 and g-C3N4, respectively. According to the trapping experiments, the superoxide radical (·O2−) was the major active species of the RhB decomposition in Bi2WO6/g-C3N4 catalysts. Originality/value: The successful synthesis of Z-scheme Bi2WO6/g-C3N4 provides new ideas and references for the design of catalysts with high photocatalytic activity, which should have wide applications in the future. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation of oxytetracycline hydrochloride (OTC‐HCl) in marine aquaculture wastewater and therefore the effects of factors on the effectiveness of photocatalysts are studied in this paper using Zn0.75Mn0.75Fe1.5O4/ZnFe2O4/ZnO under visible light and changing the molar ratio of Zn2+:Fe3+:Mn2+, calcination temperature of catalysts, hydrogen peroxide concentration, dose of catalysts, illumination time of photocatalytic and initial concentration of OTC‐HCl. The degradation of OTC‐HCl in marine aquaculture wastewater was optimized by orthogonal experiment. The best effect exists when the molar ratio of Zn2+:Fe3+:Mn2+ was 10:1:3, the calcination temperature of photocatalyst was 400°C, the concentration of hydrogen peroxide was 0.5 g/L, the dose of catalysts was 0.6 g/L, the illumination time was 2.5 h and the initial concentration of OTC‐HCl was 0.010 g/L. The degradation rate of OTC‐HCl can reach 80.18%. Zn0.75Mn0.75Fe1.5O4/ZnFe2O4/ZnO can effectively degrade the OTC‐HCl in marine aquaculture wastewater under visible light. [ABSTRACT FROM AUTHOR]

In this paper, ultra‐thin g‐C3N4 nanosheets were prepared by improved ultrasonic stripping method for the first time. Then, g‐C3N4 nanosheets were pretreated into Bi+/g‐C3N4 nanosheets by electrostatic adsorption principle, and a new type of Cl‐Bi2WO6/g‐C3N4 heterostructure photocatalyst was prepared by using Bi+/g‐C3N4 nanosheets as the substrate. The degradation of RhB under photocatalysis was studied with the compound amount of g‐C3N4 and the amount of catalyst by using x‐ray diffraction (XRD), a scanning electron microscope (SEM), high‐resolution transmission electron microscopy (HRTEM), x‐ray photoelectron spectroscopy (XPS), Brunauer Emmett‐Teller (BET), and ultraviolet visible diffuse (UV‐vis DRS) methods on the structure, morphology, and optical characterization charge transfer characteristics, etc. The results of the degradation experiment show that the compound appropriate amount of g‐C3N4 can significantly improve the activity of the photocatalyst. At the same time, different amounts of Cl‐Bi2WO6/g‐C3N4 composite photocatalyst have a significant effect on the degradation performance, and the photocatalytic activity is the best when the input is 2 g/L. Combined with active species capture experiments, a possible degradation mechanism of Cl‐Bi2WO6/g‐C3N4 Z‐type heterostructure photocatalyst was proposed. [ABSTRACT FROM AUTHOR]

The synthesis and development of cost-effective and high-efficiency adsorption-photocatalysis bifunctional treatment agents for uranium-containing wastewater is of great importance. In this work, we successfully synthesized layered double hydroxides (LDHs, NiAl and ZnNiAl) with different nickel coordination environments and investigated the adsorption activity and photocatalytic removal performance of uranium (U(VI)) under visible light. The adsorption experimental results showed that the adsorption capacity of NiAl was about four times that of ZnNiAl, and the excellent adsorption properties of NiAl originated from its large surface area and surface Ni–OH groups, which had a high coordination ability toward U(VI). In addition, NiAl had a narrower band gap than ZnNiAls due to the electronegativity of Ni2+(1.91) being greater than Zn2+(1.65), and NiAl (0.055 h−1) exhibited a higher efficiency of U(VI) photoreduction than ZnNiAl (0.0138 h−1) under visible light. Thus, NiAl showed dual properties of adsorption and photoreduction. In the process of photocatalysis, the photogenerated electrons and generated ˙O2− radicals could reduce the absorbed U(VI) into insoluble UO2(s) and U3O8. Consequently, photocatalytic reduction could further improve the performance of NiAl in removing U(VI) from the solution. NiAl with its low cost and disposal simplicity could be exploited for the decontamination of U(VI), involving surface complexation and photocatalytic reduction. [ABSTRACT FROM AUTHOR]

Photocatalytic dye degradation is one of the simple and convenient ways to eliminate effluents produced by paper, plastic, printing, and textile industries. ZnS is one of the most investigated catalysts on which different modifications are applied. Here, PVP-assisted zinc sulfide (ZnS) nanopowder is prepared hydrothermally. The photoluminescence spectra signify the generated intermediate state which is attributed to sulfur (S) vacancy as obtained from the theoretical analysis. This defect-induced ZnS has shown excellent Rhodamine B (RhB) dye degradation of 95% in 100 min with dye sensitization effect under UV irradiation. Under visible light, the degradation of RhB is only 50% in the presence of ZnS. The sensitization of RhB in the presence of UV light signifies the generation of visible light through the intermediate states caused by S vacancy. However, to eliminate the disadvantage of photocatalysis in highly concentrated wastewater management and expense of UV source, RhB is degraded by sonocatalysis, and 70% of dye is removed within 100 min in the presence of ZnS nanopowder. Therefore, the efficient catalytic dye degradations are achieved employing the minimum amount of ZnS powder. [ABSTRACT FROM AUTHOR]

• We report a facile method for the preparation of Ln-MOFs. • The construction by design of MOFs using various multifunctional organic ligands connected through coordination bonds. • Two new materials based on MOFs present excellent adsorption properties of CO 2 over N 2. • These two complexes present excellent good photocatalytic activities for TC under visible light irradiation. Rational design of lanthanide metal-organic frameworks (Ln-MOFs) with high stability is of great significance for multifunctional applications. Ln-MOFs have attracted extensive attention in the field of photocatalysis due to their large specific surface area and strong visible light efficiency. In this paper, two 2D/3D Ln-MOFs with different spatial configurations have been successfully synthesized under solvothermal conditions, namely [La(HL)(H 2 O)] n ·3H 2 O (1), [Er(HL)·3/2(H 2 O)] n ·3/2H 2 O (2), where H 4 L = 5-(bis(3-carboxybenzyl)amino)isophthalic acid. Their structures were determined by X-ray single crystal diffraction analysis, and further characterized by XRD analysis and IR spectroscopy. The complex 1 shows layered structure, which extends into a three-dimensional (3D) supramolecular network by π-π interactions, the complex 2 exhibit 3D network structures with a Schläfli symbol of 412 · 63 topologies, respectively. BET test results showed that there were carboxylic acid groups without coordination in the structure of complex 1, with abundant active sites and higher adsorption activity than complex 2, which would promote the effective contact and reaction between the photocatalyst and tetracycline (TC), thus improving the photocatalytic efficiency of complex 1. Under visible light irradiation, complex 1 showed good photocatalytic degradation of TC, and the degradation rate of TC could reach 75.54% under 120 min. This can be attributed to the effective separation of photogenerated electron-hole pairs and adsorption properties of complex 1. This study provides a new idea for MOFs as an efficient photocatalyst to degrade antibiotic pollutants. In this paper, two 2D/3D Ln-MOFs with different spatial configurations have been successfully synthesized under solvothermal conditions with 5-(bis(3-carboxybenzyl)amino)isophthalic acid. Under visible light irradiation, complex 1 showed good photocatalytic degradation of TC, and the degradation rate of TC could reach 75.54% under 120 min. This study provides a new idea for MOFs as an efficient photocatalyst to degrade antibiotic pollutants. [Display omitted] [ABSTRACT FROM AUTHOR]