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Through a two-step solvothermal method, different molar ratios of BiPO4 were grown in situ on the surface of oxygen-vacancy-rich BiOBr (Ov-BiOBr), successfully constructing a BiPO4/Ov-BiOBr heterojunction composite material. By constructing a novel type I high-low junction between the semiconductor BiPO4 and Ov-BiOBr, stronger oxidative holes or reductive electrons were retained, thereby improving the redox performance of the photocatalyst. The composite catalyst with a 10% molar content of BiPO4 demonstrated the highest degradation rate of tetracycline (TC), degrading over 95% within 90 min, with a rate constant of 0.02534 min−1, which is 2.3 times that of Ov-BiOBr and 22 times that of BiPO4. The 10% BiPO4/Ov-BiOBr sample displayed the best photocatalytic activity, producing 139 μmol·L−1 H2O2 in 120 min, which is 3.6 times the efficiency of Ov-BiOBr and 19 times that of BiPO4. This was due to the appropriate bandgap matching between BiPO4 and Ov-BiOBr, the photo-generated electron transfer channel via Bi-bridge, and efficient charge separation. It was inferred that the free radical species ·OH and ·O2− played the dominant role in the photocatalytic process. Based on experimental and theoretical results, a possible photocatalytic mechanism was proposed. [ABSTRACT FROM AUTHOR]

Photocatalysis is a hopeful technology to solve various environmental problems, but it is still a technical task to produce large-scale photocatalysts in a simple and sustainable way. Here, nano-flower β-Bi2O3/TiO2 composites were prepared via a facile solvothermal method, and the photocatalytic performances of β-Bi2O3/TiO2 composites with different Bi/Ti molar ratios were studied. The nano-flower Bi2O3/TiO2 composites were studied by SEM, XRD, XPS, BET, and PL. The PL result proved that the construction of staggered heterojunction enhanced the separation efficiency of carriers. The degradation RhB was applied to study the photocatalytic performances of prepared materials. The results showed that the degradation efficiency of RhB increased from 61.2% to 99.6% when the molar ratio of Bi/Ti was 2.1%. It is a mesoporous approach to enhance photocatalytic properties by forming heterojunction in Bi2O3/TiO2 composites, which increases the separation efficiency of the generated carriers and improves photocatalytic properties. The photoactivity of the Bi2O3/TiO2 has no evident changes after the fifth recovery, indicating that the Bi2O3/TiO2 composite has distinguished stability. [ABSTRACT FROM AUTHOR]

Bimetallic AgCo/g-C 3 N 4 photocatalysts were successfully prepared by a facile chemical reduction method and used to investigate their photocatalytic H 2 production performance. Bimetallic AgCo as a cocatalyst can be well matched with g-C 3 N 4 , which is beneficial for increasing the number of active reaction sites and narrowing the band gap. A possible photocatalytic mechanism was explored by XRD, FTIR, SEM, TEM, UV–vis DRS, BET, and PL characterization. The photocatalytic H 2 production activity of the optimal 5%AgCo/g-C 3 N 4 photocatalyst reached 12994.2 μmoL/g, which was 54.7 times higher than g-C 3 N 4. Owing to the close interfacial contact between bimetallic AgCo and g-C 3 N 4 , the transfer distance was shortened, and the photogenerated electron and hole pairs were effectively separated. This study provides a new strategy for the synthesis of excellent H 2 production photocatalysts using bimetallic nanoparticles. • Bimetallic AgCo were loaded on g-C 3 N 4 nanosheets via chemical reduction method. • Intimate interfacial contact was facilitated the effective separation of e−-h+ pairs. • The AgCo/g-C 3 N 4 exhibited excellent photocatalytic activity and reusability. • The photocatalytic mechanism was conducive to water spitting H 2 production. [ABSTRACT FROM AUTHOR]

There are many reports on g-C3N4 nanosheet and BiOCl nanosheet, but few studies on other morphologies of g-C3N4 and BiOCl. Herein, a g-C3N4 nanoball/BiOCl nanotube heterojunction prepared by a simple one-step acetonitrile solvothermal method is reported. The XRD results prove that the g-C3N4/BiOCl composites can be prepared in one step. SEM results revealed that the g-C3N4 was spherical and the BiOCl was tubular. The HRTEM results indicate that g-C3N4 has an amorphous structure and that the (100) crystal plane of BiOCl borders the g-C3N4. Spherical g-C3N4 has a narrow band gap (approximately 1.94 eV), and the band gap of g-C3N4/BiOCl after modification was also narrow. When the BiOCl accounted for 30% of the g-C3N4/BiOCl by mass, the quasi-primary reaction rate constant of RhB degradation was 45 times that of g-C3N4. This successful preparation method for optimizing g-C3N4 involving simple one-step template-free synthesis may be adopted for the preparation of diverse-shapes and high-performance nanomaterials in the future. [ABSTRACT FROM AUTHOR]

Z-scheme heterostructure photocatalysts for the transfer and separation efficiency of carriers are increasingly popular. CdS nanoparticle decorated three-dimensional (3D) flower-like Zn3(PO4)2 nanostructures were prepared through a simple hydrothermal route and precipitation methods. The CdS/Zn3(PO4)2 heteronanostructures were characterized through X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), UV-visible light spectroscopy (UV-vis), photoluminescence (PL) spectroscopy and photoelectrochemical measurements. The results showed that the three-dimensional flower-like structure of Zn3(PO4)2 composed of two-dimensional nanoplates and CdS/Zn3(PO4)2 heteronanostructures was obtained. The results of the Mott–Schottky measurements and the active species trapping experiments suggested that a Z-scheme system between the CdS nanoparticles and Zn3(PO4)2 nanoplates was formed. Meanwhile, the CdS/Zn3(PO4)2 heteronanostructures exhibited much higher photocatalytic activity for the degradation of MB under visible light, and that of the CdS/Zn3(PO4)2-13 heteronanostructure with excellent photocatalytic stability is nearly 3.04 times higher than that of pure Zn3(PO4)2 nanostructures. [ABSTRACT FROM AUTHOR]

The green treatment of dye wastewater has always been a research hotspot in the environmental field. The photocatalytic technology is considered to be a simple and effective strategy to remove dyes in wastewater. A new type of NiWO4/WO3 Z-scheme heterojunction microspheres were synthesized by a simple hydrothermal method and impregnation-calcination process. The crystal structure, microscopic morphology, optical and electrochemical properties of the samples were systematically characterized. The photocatalytic activity of methylene blue (MB) was studied by visible light irradiation. The results show that the direct Z-scheme heterojunction formed by NiWO4/WO3 effectively reduces the transfer resistance of photogenerated carriers and improves the separation efficiency of photogenerated carriers. The degradation rates of NiWO4/WO3-4 Z-scheme heterojunction microspheres to MB dye are 1.8 and 3.2 times higher than that of pure WO3·2H2O and WO3 microspheres, respectively. Combined with the Mott–Schottky curve and the active species capture experiments, a possible Z-scheme photogenerated carrier transfer mechanism is proposed. This study provides a method for the development and design of Z-scheme heterojunction photocatalysts in the field of wastewater purification. [ABSTRACT FROM AUTHOR]

In this work, Co-doped BiOBr prepared by cation-exchange strategy exhibits excellent photocatalytic performance under visible light in pure water. The Co-BiOBr-0.5 catalyst presents a better evolution rate of of CO 2 photoreduction to CO, reaching 11.71 μmol·g−1 h−1, which is 3.6 times higher than pure BiOBr. In addition, UV-Vis results show that the synthetized Co-doped BiOBr prepared by cation exchange strategy has wider visible light response. Meanwhile, TPR, EIS and PL results show that the cation exchange strategy can improve the electron-hole separation efficiency of BiOBr. This work might provide a simple method for preparing efficient photocatalysts for CO 2 reduction. [Display omitted] • Innovation in the use of cation-exchange strategy for the preparation of Co-BiOBr. • Cation-exchange strategy improves the light absorption and electron-hole separation efficiency of BiOBr. • The CO yield of Co-BiOBr-0.5 is as high as 11.71 μmolg−1h−1. • Cation exchange strategies offer new options for the preparation of high-performance catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel heterostructured ZnFe 2 O 4 /Bi 2 MoO 6 photocatalyst is conducted. • The formed heterojunction promotes transfer of charge carriers. • ZnFe 2 O 4 /Bi 2 MoO 6 shows superior photocatalytic activity for CO 2 reduction. • The main active species during photocatalytic process is e−. A novel ZnFe 2 O 4 /Bi 2 MoO 6 heterojunction photocatalyst was synthesized by a facile solvothermal route. The incorporation of a narrow bandgap ZnFe 2 O 4 photocatalyst can efficiently improve the range of light response and light absorption capacity of the Bi 2 MoO 6 via the formation of a hybrid structure at the interface. The formed hybrid interface facilitates the separation efficiency of photo-generated carriers at ZnFe 2 O 4 /Bi 2 MoO 6 heterojunction significantly. The experimental results confirm that ZnFe 2 O 4 /Bi 2 MoO 6 -20% heterojunction showed the highest photocatalytic efficiency for CO 2 reduction. Specifically, the total product yield of 47.1 μmol g−1 under 5 h simulated sunlight irradiation is measured in the counterparts of pure ZnFe 2 O 4 (14.79 μmol g−1) and pure Bi 2 MoO 6 (19.01 μmol g−1). Indeed, the formation of ZnFe 2 O 4 /Bi 2 MoO 6 heterojunction improved the photocatalytic efficiency for CO 2 reduction. [ABSTRACT FROM AUTHOR]

Due to its low photogenerated carrier separation efficiency and wide band gap, the photocatalytic activity of TiO 2 is not ideal. In this work, CeCO 3 OH/TiO 2 composites were successfully prepared by a simple hydrothermal method. A series of characterisations shows that the CeCO 3 OH/TiO 2 composites improves the photogenerated carrier separation efficiency, narrowes the band gap width and increases the visible light absorption capacity compared with the monomer, enhancing the photocatalytic hydrogen evolution performance. Under visible light irradiation, 20% CeCO 3 OH/TiO 2 exhibites the highest photocatalytic hydrogen production performance of 2386.16 μmol g−1 h−1, which is 18.7 times higher than that of pure TiO 2 and 25.8 times higher than that of pure CeCO 3 OH. It provides ideas for the development of more efficient photocatalytic materials and technologies. • CeCO 3 OH loading on the TiO 2 surface promotes the separation of photogenerated carriers. • 20% CeCO 3 OH/TiO 2 has the best photocatalytic performance, which is 18.7 and 25.8 times higher than TiO 2 and CeCO 3 OH. • A possible mechanism for photocatalytic hydrogen production is proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of Bi in benzene-ring-grafted g-C 3 N 4 were prepared by a facile method. • The introduction of the benzene-ring enhances the charge separation efficiency. • A CO yield rate of 8.17 μmol/g·h was achieved via this strategy. Graphitic carbon nitride (g-C 3 N 4) holds a prominent position in the field of photocatalysis and represents one of the most promising non-metallic catalysts at present. However, its inherent defects undermine its photocatalytic activity, thus limiting its practical applications. To address this issue, we employed transition metal bismuth spheres, which were dispersed and anchored on benzene-ring-grafted porous g-C 3 N 4 nanosheets, for the photocatalytic reduction of CO 2 via a simple solvothermal synthesis method. The experimental results revealed that Bi-BCN-0.2 exhibited the highest photocatalytic CO 2 reduction, yielding 8.17 μmol/(g·h) of CO, which was 21 times greater than CN (0.39 μmol/(g·h)) and 8.5 times greater than BCN (0.95 μmol/(g·h)). Through relevant characterization, we found that the introduction of benzene rings in the CN skeleton resulted in an expansion of π-electron delocalization, leading to improved the efficiency of charge separation upon photoexcitation. Additionally, the further loading of Bi sphere co-catalysts, forming Schottky junctions, effectively inhibited the recombination of photogenerated electron-hole pairs and promoted photogenerated charge transfer. Furthermore, the SPR (surface plasmon resonance) effect enhanced the light harvesting ability. These modifications collectively contributed to enhancing the photocatalytic activity of g-C 3 N 4 and introduced a novel approach for utilizing g-C 3 N 4 in the photocatalytic reduction of CO 2. [ABSTRACT FROM AUTHOR]

• The heterostructural 2D/1D BiOBr/CdS composites were prepared by hydrothermal method. • The composites display more effective charge separation and migration. • The composites present a high CO production rate of 13.6 μmol g−1. Herein, a generalizable strategy using the solvothermal process to obtain the heterostructural composites between BiOBr nanosheet and CdS nanorods is presented. Using a facile hydrothermal method, the CdS nanorods were anchored onto BiOBr nanosheets with average scales ranging from 10 to 500 nm to build up the heterostructure. The improvement of the efficiency of charge separation through the construction of 2D/1D heterojunction was confirmed by SEM, TEM, XPS, photocurrent, and AC impedance. CO 2 photoreduction was employed to study the photocatalytic activities of the as prepared composites. The heterostructural BiOBr/CdS composites owned better activity than both the pure BiOBr nanosheets and pure CdS nanorods. Most significantly, the yield of CO during photocatalytic reduction reaction with BiOBr/CdS-5% catalyst was measured to be 13.6 μmol g−1, which was 1.8 times larger than that with BiOBr nanosheets and 6.4 times larger than that with CdS nanorods during 3 h simulative sunlight exposure. The optimized photocatalytic property of heterostructural BiOBr/CdS-5% composite could be attributed to the wide sunlight response range, large specific surface area, and effective separation of photoelectrons-holes from the heterostructure between BiOBr nanosheets and CdS nanorods. [ABSTRACT FROM AUTHOR]

• Constructed BiOBr/In 2 O 3 II-type heterojunction composites using a simple hydrothermal method. • BiOBr/In 2 O 3 heterojunction interfaces facilitate electron transport. • BiOBr/In 2 O 3 –2 % exhibits good selectivity for reduction with a CO 2 reduction energy of 9.81 μmol·g−1·h−1. The advancement of catalysts featuring high carrier separation efficiency enhances photocatalytic reduction performance. This study employed a simple hydrothermal method to anchor In 2 O 3 nanoparticles onto the surface of two-dimensional BiOBr nanosheets, constructing a type-II heterostructure that improves the photocatalytic reduction capability. The composites of 0D/2D In 2 O 3 /BiOBr underwent XPS, TPR, and MS characterization, validating the formation of a type-II heterostructure. In 2 O 3 functioned as an electron-aggregating active site that extracted photogenerated electrons from the surface of BiOBr. As a result, the efficiency of charge separation is markedly increased. The results of the CO 2 reduction test indicate that In 2 O 3 -modified BiOBr exhibits superior photocatalytic activity compared to pure BiOBr, with 2 % In 2 O 3 /BiOBr exhibiting the highest reduction performance. The CO yield achieved was 9.81 µmol·g−1·h−1, which is 5.33 times higher than that of pure BiOBr and 42.65 times higher than that of pure In 2 O 3. These findings offer future potential for the application of In 2 O 3 as an electron-accumulating material to enable the photocatalytic reduction of CO 2. [ABSTRACT FROM AUTHOR]

This research provides a innovatively designed mechanism of activating the passivation layer on Fe0 surface as semiconductor to construct a Z-scheme heterojunction in-situ for high-efficiency environmental remediation. Aggregation and passivation of Fe0 and poor visible-light absorption of TiO 2 were simultaneously improved by the facile synthesis of a recyclable Fe0@black-TiO 2 Z-scheme heterojunction without high-temperature hydrogen atmosphere. The results showed that tetracycline (TC) degradation efficiency with Fe0@black-TiO 2 was 1.23 and 2.63 times higher than that of pristine Fe0 and black-TiO 2 , respectively. The superior degradation arose from strong reduction ability of highly dispersed Fe0 and in-situ constructed Z-scheme heterojunctions. High dispersion of Fe0, construction of the heterojunction, enhanced photodegradability of Fe0@black-TiO 2 were systematically elucidated by multiple characterization techniques. Furthermore, photodegradation pathways of TC based on the role of •O 2 - and •OH were identified. Our results have provided the necessary inspiration and guidance for the development and application prospect of Fe0@black-TiO 2 in environmental remediation. A facile recyclable Fe0@b-TiO 2 with highly dispersed Fe0 exhibits excellent reduction ability and constructs a Z-scheme heterojunction in-situ in the dark reaction, which is beneficial to the separation of photo-generated electron-hole pairs, the migration of carriers and the generation of highly active ROS (•O 2 -, •OH) during the photodegradation process, further realizing enhanced visible-light-driven photocatalytic ability for TC. [Display omitted] • Facile synthesis of Fe0@black-TiO 2 with strengthened visible-light photocatalysis. • Enhanced TC removal via strong synergistic adsorption, reduction and photocatalysis. • Highly dispersed Fe0 induced by black TiO 2 guarantees strong reduction ability. • In-situ constructed Z-scheme heterojunctions ensure superior photodegradation. • Novel heterojunctions of Fe0 and black TiO 2 lead to dramatically improved activity. [ABSTRACT FROM AUTHOR]

Designing and fabricating the double-capability photocatalysts with the capability of producing hydrogen from the splitting of water and degrading environmental organic pollutants under visible light irradiation are significant in environmental treatment and new energy preparation. As a proof of concept, TiO 2 @ZnFe 2 O 4 heterojunctions with high performance and stability were prepared by a one-step hydrothermal method, in which TiO 2 nanosheets successfully grew on the main body of ZnFe 2 O 4 nanorods. The microstructures and morphologies of the as-produced composites as well as their photocatalytic hydrogen generation rate and photocatalytic degradation performances towards humic acid, florfeniol, tetracyclines, and bisphenol A were investigated. The results indicate that TiO 2 @ZnFe 2 O 4 heterojunctions possessed the higher photocatalytic activities towards hydrogen production and contaminants degradation ability than that of only TiO 2 and ZnFe 2 O 4. Especially, TiO 2 @ZnFe 2 O 4 heterojunctions with the molar ratio of 1:4 have the best activities and manifest good stability. Significant enhancement of visible light absorption and photogenerated charge separation of TiO 2 @ZnFe 2 O 4 were achieved. This work paves a way to construct a low-cost, environment-friendly, recyclable, and non-poisonous photocatalysts for hydrogen generation and the degradation of pollutants. [Display omitted] • TiO 2 @ZnFe 2 O 4 heterojunctions have been prepared and used as double-capability photocatalysts. • The catalyst possessed the enhanced photocatalytic activities for hydrogen production. • The heterojunction can also degrade humic acid, florfeniol, tetracyclines, and bisphenol A. • The heterojunctions can effectively separate the photogenerated electrons and holes. • The formation of the heterojunction can enhance the photocatalytic activity. [ABSTRACT FROM AUTHOR]

BiOBr (BOB) photocatalysts have low photocatalytic CO 2 reduction performance due to their low electron-hole pair separation efficiency. To improve this problem, BiOCl (BOCl) is used as a co-catalyst. BOCl is loaded into BOB to form BiOCl/BiOBr (BOCl/BOB) type Ⅰ heterojunction, which enhances the photocatalytic CO 2 reduction performance of BOB by promoting the separation of photogenerated electrons and holes. The results of TPR and PL experiments show that the 20% BOCl/BOB composites have the highest photogenerated carrier separation rate, and the results of CO 2 reduction experiments show that 20% BOCl/BOB composites have the best photocatalytic CO 2 reduction performance of 7.353 μmolg−1h−1, which is 3.22 and 1.99 times higher than pure BOB and BOCl, respectively. This work provides an effective reference for the development of modified photocatalysts. [Display omitted] • BOCl promotes BiOBr photogenerated carriers separation. • The photocatalytic CO 2 reduction performance reached 7.353 µmol g−1 h−1. • A possible mechanism for photocatalytic CO 2 reduction is proposed. [ABSTRACT FROM AUTHOR]

In this work, the BiOCl/In 2 O 3 catalyst for the photocatalytic reduction of CO 2 was successfully prepared by the hydrothermal method and the type II heterojunction was successfully constructed. The photocatalytic activity of the complex catalyst for the photocatalytic reduction of CO 2 was investigated. The results show that the photocatalytic yield of the BiOCl/In 2 O 3 composite to CO is 6.9 µmolg−1h−1, which is 3.6 and 35 times that of BiOCl nanosheets and In 2 O 3 , respectively. The BiOCl/In 2 O 3 composite photocatalyst has better visible light absorption and better charge separation efficiency. The significant improvement in the photocatalytic performance can be attributed to the improvement in the visible light absorption range and the reduced band gap, which can increase the production of photogenerated electrons and thus facilitate the reaction of CO 2 reduction to CO. [Display omitted] • Two-dimensional BiOCl nanosheets modified with In 2 O 3 nanoparticles were successfully synthesized. • 1 %BiOCl/In 2 O 3 exhibits good selectivity for reduction with a CO 2 reduction energy of 6.9 µmolg−1h−1. • BiOCl/In 2 O 3 composites have significantly enhanced CO 2 to CO activity. [ABSTRACT FROM AUTHOR]

Although both MoS 2 and nanoscale zero valent iron have presented bright prospects for environmental remediation. The constrained conductivity of MoS 2 and the passivation and aggregation of Fe0 still retained challenges. Given this, innovative strategies of activating the passivation layers of Fe0 into semiconductors by photocatalysis and constructing S-scheme nanoflower heterojunctions with MoS 2 (Fe0@MoS 2) were fabricated. The results revealed that Fe0@MoS 2 exhibited enhanced efficiency toward visible-light degradation of tetracycline, which was 3.20 and 1.27 times as high as that of bare MoS 2 and Fe0, respectively. The boosted activity was attributed to the cooperation of MoS 2 and Fe0. The synergistic effects stemmed from the following mechanisms: (1) the fluffy nanoflower-like structure and widened interlayer spacing of MoS 2 facilitated the dispersion of Fe0, guaranteeing its enhanced adsorption and reduction capacity; (2) the conductivity of MoS 2 was remarkably improved due to the doping of the passivation layers of Fe0, and the layers were activated as semiconductors by visible-light, causing the establishment of S-scheme heterojunctions between them and MoS 2. Moreover, the kinetics, stability, recyclability, and optical characteristics of Fe0@MoS 2 were confirmed comprehensively. The potential routes for TC elimination deriving from the action of •O 2 − and h+ were proposed. These findings provided novel strategies for construction of Fe0-based S-scheme heterojunction with advanced visible-light-induced degradation performance. [Display omitted] • Synergistic effect of Fe0 and MoS 2 activates superior TC degradation. • Fluffy nanoflower-like structure of MoS 2 ensures strong reduction ability of Fe0. • Fe0 widens the layer spacing and its oxide layer boosts the conductivity of MoS 2. • MoS 2 and the oxide layer of Fe0 construct S-scheme nanoflower heterojunctions. • Novel and efficient heterojunctions exhibit promising properties and applications. [ABSTRACT FROM AUTHOR]

• The heterostructural 2D/2D BiOBr/Zn(OH) 2 composite was prepared by direct precipitation polymerization. • The composite displays more effective charge separation and migration. • The composite presents a high CO production of 16.21 μmol g−1. For the sake of enhancing the photocatalytic performance of BiOBr, 2D Zn(OH) 2 nanosheets were introduced on 2D BiOBr nanosheets to construct a 2D heterosturcture in BiOBr/Zn(OH) 2 composites by direct precipitation polymerization. After depositing Zn(OH) 2 , the specific surface areas of BiOBr/Zn(OH) 2 composites were improved, which resulted in more active sites. Meanwhile, the synergistic action between Zn(OH) 2 and BiOBr can adjust the band-gap, enhancing the light absorption and reducing the charge transfer resistance. BiOBr/Zn(OH) 2 composites possessed the better separation efficiency of photogenerated carriers. Meanwhile, the results showed that the ability of photocatalytic CO 2 reduction was improved. Under 3 h simulated sunlight irradiation, BiOBr/Zn(OH) 2 –10% showed the highest performance of photocatalytic CO 2 reduction, and the total output of photocatalytic reduction product CO was 16.21 μmol g−1, which is 2.2 times than that of BiOBr. [ABSTRACT FROM AUTHOR]

• BiOBr/CoAl-LDH heterojunctions with suppressed Z-axis growth were prepared. • The closely contact between heterojunctions were proved. • A highly CO 2 photoreduction performance was achieved. • The deep mechanism during the photocatalytic reaction was investigated. Due to the massive usage of fossil fuels, the carbon dioxide content in the atmosphere is increasing year by year. Meanwhile, the CO 2 photoreduction has been widely researched and regarded as a promising method to utilize the CO 2. BiOBr has good photocatalytic activity as a suitable photocatalyst. However, the photocatalytic performance is still unsatisfactory, and the product of CO 2 photocatalytic reduction has a large proportion of CO instead of CH 4. Therefore, in this paper, we prepare ultrathin CoAl-LDH by inhibiting Z-axis growth and load ultrathin CoAl-LDH on BiOBr to construct heterojunction to improve the photocatalytic efficiency of BiOBr and regulate the selectivity of the products. It was found that the loading of ultrathin CoAl-LDH helps to improve the photogenerated electron-hole pair separation ability and photogenerated carrier transport ability, thus improving the photocatalytic performance. At the same time, the loading of ultrathin CoAl-LDH helps to convert the photocatalytic CO 2 reduction product from CO to CH 4. After the gradient study experiment on the dosage of ultrathin CoAl-LDH, it was found that the best effect was achieved at the dosage of 10 mL of ultrathin CoAl-LDH colloidal solution, and the CO yield rate was 4.096 μmol·g−1·h−1 and CH 4 yield rate was 4.174 μmol·g−1·h−1. Meanwhile, the CH 4 selectivity will reach 46% of the product. In this work, we offer a novel regulation strategy for selectivity improvement of CO 2 photocatalytic reduction, which can be assigned to the moderated ultrathin CoAl-LDH loading, thus enhance the selectivity of CO 2 to CH 4. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two pair of analogous conjugated polymers containing dibenzo[ b , d ]thiophene sulfone are synthesized. • The polymers containing dual pyridinic N atoms have much higher HPR than their analogues. • The dual pyridinic N atoms and sulfone units are equally effective HER active sites. • The dual pyridinic N atoms perform a parallel HER role to that of the sulfone unit. • The experimental results are consistent with the theoretical calculation results. Research a new type of semiconductor photocatalyst and apply it to photocatalytic water splitting to produce hydrogen. This is the most important topic in today's society. Therefore, we report four linear organic polymers PH-1, PH-2, PN-1 and PN-2, which are formed by the condensation of dibenzothiophene- S, S -dioxide units with a series of derivatives of benzene respectively and used for photocatalytic hydrogen evolution. What's more, we also conducted a series of detailed characterization experiments on the four polymers, such as UV–vis, XPS, XRD, etc., to explore their molecular structure and optical properties. Compared with the polymer PH-1 and PH-2, the polymer PN-1 and PN-2 containing nitrogen element can better adjust the structure, reduce the band gap value, increase the specific surface area, and accelerate the separation of electrons and holes, PN-2 had the highest hydrogen evolution rate of 6658 μmol g−1 h−1 among four polymers without Pt as the co-catalyst under full arc irradiation. This work not only synthesized the four photocatalysts, but also opened up a new way for the conversion of solar energy into chemical fuels. [ABSTRACT FROM AUTHOR]

In this work, type II heterojunctions were constructed by in suit loading of ZnIn 2 S 4 (ZIS) nanosheets onto S-doped g-C 3 N 4 (SCN) nanosheets by a simple hydrothermal synthesis method. The formation of heterojunction induced rapid electron-hole separation, while the introduction of SCN reduced the internal resistance of photogenerated carriers to transfer. When the mass fraction of SCN was 20 %, the best photocatalytic hydrogen production performance was 1.63 mmol g−1 h−1 under visible light irradiation (λ > 420 nm), which was 7.7 and 2.8 times higher than SCN (0.21 mmol g−1 h−1) and ZIS (0.57 mmol g−1 h−1), respectively. The enhanced photocatalytic activity was mainly due to greater light utilization achieved by band gap adjustment through constructing heterojunctions and improved electron-hole separation efficiency. This method can effectively improve the photocatalytic performance of ZIS-based photocatalysts in a simple way. [Display omitted] • ZnIn 2 S 4 (ZIS) nanosheets were loaded in situ on S doped g-C 3 N 4 (SCN) nanosheets by a simple hydrothermal synthesis method. • Type II heterojunction can expand the light utilization and improve the electron-hole separation efficiency. • The best photocatalytic performance of 20%-SCN/ZIS heterojunction reached 1.63 mmol g−1 h−1 under visible-light irradiation. [ABSTRACT FROM AUTHOR]

• The N, F codoping in TiO 2 NTs were carried out by solvothermal-assisted annealing treatment. • The codoped photoelectrode displayed the attractive photocatalytic performance. • The preparation and doping mechanism were explored. [Display omitted] By the exploitation of doping in semiconductor photocatalysts, the energy band structure adjustment would induce the improvement of solar absorption and photochemical performance. Here, we investigated the N/F codoped TiO 2 nanotube arrays (TiO 2 NTs) by tuning the preparation operation sequence of solvothermal doping and annealing treatment. The optimized Sample 1 prepared by the first solvothermal doping in ethanol and then annealing exhibited the outstanding solar absorption, low electron-hole recombination and photoelectrochemical performances. The excellent photocatalytic performances in photocurrent/H 2 generation and pollutant removal were discussed and analyzed in detail. Furthermore, we explained the mechanism of N/F codoping for improved photocatalytic performances. The work gives a referable template for improved photocatalytic application fields of TiO 2 in environment and energy. [ABSTRACT FROM AUTHOR]