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One of the major challenges in photocatalytic hydrogen production is to improve the separation efficiency of photo-generated carriers. Therefore, we prepared ZIS/BMO heterojunctions by hydrothermal method to promote the directional separation of photogenerated carriers. A series of characterization results show that the successful preparation of heterojunctions substantially increases the separation and transfer rate of photogenerated carriers. 11% ZIS/BMO had the highest photocatalytic hydrogen production performance reached 1502.6 μmol/g/h, which is 2.78 times than ZIS monomer. Simple construction of heterojunctions but dramatic improvement of photocatalytic hydrogen production performance opens up new horizons for photocatalyst modification. • A series of ZnIn 2 S 4 /Bi 2 MoO 6 heterojunction photocatalysts were prepared by a facile method. • The charge transfer and separation efficiency was enhanced. • A hydrogen production rate of 1502.6 μmol/g/h was achieved via this strategy. [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]

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]

A Z-scheme polypyrrole/Bi 2 SiO 5 heterojunction rich in oxygen vacancies was prepared by combining the organic polymer polypyrrole with Bi 2 SiO 5 via a hydrothermal method and an oxidative polymerization reaction. The photocatalyst exhibited good stability in water and effectively degraded tetracycline, oxytetracycline, ciprofloxacin, norfloxacin, and doxycycline under simulated sunlight, indicating its excellent potential for wastewater treatment. In particular, the efficiency of tetracycline removal by the optimized polypyrrole/Bi 2 SiO 5 composite after 120 min of irradiation was 93.1%, approximately 2.1 times that of Bi 2 SiO 5. The exceptional photocatalytic performance of polypyrrole/Bi 2 SiO 5 stemmed from the construction of a Z-scheme heterostructure and generation of oxygen vacancies induced by the introduction of polypyrrole. Furthermore, liquid chromatography–mass spectrometry (LC-MS) was used to investigate the intermediate products of tetracycline degradation, and possible degradation pathways were deduced. Finally, a possible photocatalytic mechanism was proposed based on the results of electron paramagnetic resonance and free radical capture experiments. [Display omitted] • A Z-scheme polypyrrole/Bi 2 SiO 5 heterojunction photocatalyst was designed. • Polypyrrole/Bi 2 SiO 5 had rich oxygen vacancies. • Polypyrrole/Bi 2 SiO 5 could degrade various antibiotics including tetracycline. • The removal efficiency of tetracycline was 93.1% in 120 min by polypyrrole/Bi 2 SiO 5. [ABSTRACT FROM AUTHOR]

• Ion exchange strategy is used for the samples preparation. • The closely contacted heterojunction interface will facilitate the electron transport. • The high production rates of CO is obtained. • The selectivity of CO 2 photoreduction is well. CO 2 reduction via photocatalytic is regarded as the excellent strategy to resolve the severe environmental crisis and energy crisis caused by the accelerated utilization of fossil energy like natural gas, oil, and coal. The Ag ion and the Br ion in BiOBr are creatively used in the ion exchange strategy to form AgBr on the surface of BiOBr, and an S-scheme BiOBr/AgBr heterojunction with close interface contact is constructed. The visible light utilization rate and CO 2 conversion rate of the obtained heterojunction are both remarkably improved. The reduction rate of CO 2 over the catalyst was tested under visible light using pure water as the liquid environment. As obtained results displayed that the transformation efficiency of BA-1 to CO from CO 2 in the visible light was 12.43 μ mol g-1h−1, which is about 3 times that the pristine BiOBr. The intermediates during the reaction were studied using in situ DRIFTS. The process by which CO 2 was degraded was speculated based on in situ DRIFTS spectra. In addition, TPR, EIS, and PL measurements indicate that BA-1 has a high solar utilization rate and strong photo-generated carrier transfer and separation capability. This work showed a novel direction for preparation of efficient photocatalyst for CO 2 reduction. [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]

The high recombination rate of photogenerated electron-hole seriously affects the photocatalytic hydrogen production performance of TiO 2. Meanwhile, the lack of clarity of the active species in photocatalytic hydrogen production poses a certain obstacle for catalyst modification. To solve this problem, TiO 2 /SnIn 4 S 8 (TS) type II heterojunctions were prepared in this study, and TS composites achieve rapid separation and fast transfer of electron-hole. TPR results showed that the photocurrent of TS-10 increased from 2 μA/cm2 to 14 μA/cm2. In addition, the results of active species trapping experiments showed that the superoxide radicals (·O 2 -) were the main active species in the photocatalytic hydrogen production of TS-10. As a result, TiO 2 /SnIn 4 S 8 exhibited highly efficient photocatalytic hydrogen production performance. The hydrogen production rate of the optimal ratio of TS-10 reached 1603.47 μmolg-1h-1, which was 16 times higher than that of pure TiO 2 , and the apparent quantum efficiency (AQY) reached 2.064%. This study clarifies the active species in photocatalytic hydrogen evolution and provides new ideas for designing materials with high photocatalytic hydrogen evolution performance. • Effective reduction of electron-hole pair compounding efficiency. • It is clarified that ·O 2 - is the active species in the photocatalytic hydrogen production of TS composites. • The best photocatalytic H 2 performance is 1603.47 μmolg-1h-1, which was 16 times higher than pure TiO 2. [ABSTRACT FROM AUTHOR]

• BiOBr nanosheets modified with NH 2 -UiO-66 were successfully synthesized. • 1 % BiOBr/NH 2 -UiO-66 has good reducing properties with a CO yield of 9.19 µmolg-1h−1. • The BiOBr/NH 2 -UiO-66 type II heterojunction was constructed. As a typical semiconductor catalyst, BiOBr has an advisable bandgap, superior light absorption properties, and a unique laminated structure. However, the slow electron-hole separation rate results in poor CO 2 reduction performance. To enhance the photocatalytic efficiency of BiOBr, this study constructs BiOBr heterojunctions with Lewis basic groups by loading NH 2 -UiO-66 on BiOBr. The BiOBr/NH 2 -UiO-66 heterojunction have been built and possess stronger light response, larger specific surface area and electron-hole separation efficiency compared to pure BiOBr and NH 2 -UiO-66. The optimal BiOBr/NH 2 -UiO-66 displays that the CO yield is 9.19 μmol g-1h−1, which is 4 times higher than pure BiOBr. [ABSTRACT FROM AUTHOR]

A high-low heterojunction composite, oxygen vacancies BiOBr induced Bi precipitation Bi@O V -BiOBr/Cu 3 P with Bi-O-P chemical bond, was synthesized using a solvothermal method. Compared to single substance, the carrier lifetime and separation rate of Bi@O V -BiOBr/Cu 3 P were significantly improved. According to theoretical calculations and experimental results, Cu 3 P can be considered as a hole extractor to accelerate the separation of photogenerated carriers. The successful construction of Bi@O V -BiOBr/Cu 3 P high-low heterojunction with Bi metal can not only activate water molecules and reduce the dissociation energy barrier of water, but also separate and retain the highly reductive electrons. Bi metal and Cu 3 P with low valent play a crucial role in dual-channel charge transfer. Bi@O V -BiOBr/Cu 3 P exhibits the highest hydrogen evolution rate up to 723.85 μmol·cm−2·h−1. It also displays excellent photoelectrocatalytic hydrogen production stability. The boosting hydrogen production activity and stability of Bi@O V -BiOBr/Cu 3 P are attributed to the construction of high-low heterojunctions and the dual-channel charge transfer mechanism. [Display omitted] • Bi@O V -BiOBr/Cu 3 P high-low heterojunction connected by Bi-O-P bond was firstly prepared. • Bi@O V -BiOBr/Cu 3 P displays superior photoelectrochemical hydrogen evolution activity and stability. • Electron-hole dual-channel charge transfer effect facilitates swift charge separation and transfer. [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]

• A novel CdLa 2 S 4 /Ni 2 P catalyst with excellent photocatalytic H 2 evolution was introduced. • Catalyst with 15 % Ni 2 P dosage exhibited maximum photocatalytic H 2 evolution rate as 1.143 mmolh-1g−1, which was 10 times higher than that of pure CdLa 2 S 4. • The heterojunction structure formed by Ni 2 P and CdLa 2 S 4 improved the separation efficiency of photogenerated electron-hole pairs, thus prompted the H 2 evolution ability and the catalyst stability. Metal sulfides, often exhibited excellent photocatalytic H 2 evolution ability, has attracted more and more attention, whereas their industry applications were limited due to the photocorrosion. Therefore, the inhibition of photocorrosion is the key issue to promote the industrialization of metal sulfide catalysts. In this work, CdLa 2 S 4 /Ni 2 P catalysts with satisfactory H 2 evolution property were designed and synthesized. Catalyst with 15 % Ni 2 P dosage exhibited maximum photocatalytic H 2 evolution rate as 1.143 mmolh-1g−1, which was 10 times higher than that of pure CdLa 2 S 4. Such high catalytic efficiency maintained after 5 photocatalytic cycles. According to the results of transient photocurrent and photoluminescence, the heterojunction structure formed by Ni 2 P and CdLa 2 S 4 improved the separation efficiency of photogenerated electron-hole pairs, thus prompted the H 2 evolution ability and the catalyst stability. Further EPR results confirmed the existence of heterojunctions in the catalyst and proposed a possible reaction mechanism. The results show that the CdLa 2 S 4 /Ni 2 P composite photocatalyst has good visible light response and photochemical stability, and has broad application prospects in solar driven photocatalytic decomposition of water to hydrogen production. [ABSTRACT FROM AUTHOR]

TiO 2 nanotube arrays (TiO 2 NTs) were regarded as the outstanding semiconductors for the photocatalytic application in waste water treatment and H 2 generation, and CdS nanoparticles as the visible light sensitizers were traditionally used to enhance the photocatalytic performance. In this paper, CdS–CuS co-sensitizers were deposited on TiO 2 NTs by one-pot hydrothermal method, and the Cu/Cd ratio was changed to adjust the hybrid photocatalyst composition and electron transfer. The photocatalytic data indicated that suitable CdS–CuS composition could effectively enhance the photocatalytic pollutant removal and photocurrent/H 2 evolution and the hybrid photocatalyst also exhibited the high stability by the inhibition of CdS photocorrosion. The p-n heterojunction construction of TiO 2 NTs/CdS–CuS benefited the solar response, photoelectron separation and photocatalytic reaction, and the photocatalytic mechanism and photoelectron transfer were investigated. The p-n heterojunctional photocatalyst is supposed to apply in environmental remediation and new energy development. [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]

[Display omitted] • Hybridization strategy to address CO 2 adsorption and photogenerated carrier separation simultaneously. • The CO evolution of BN-15 reached 121.8 μmol g−1 h−1, which is 5 times higher than pure BiOBr. • A possible mechanism of photoreduction of CO 2 by hybrid material is proposed. The low electron-hole separation efficiency and poor CO 2 adsorption of BiOBr limit its photoreduction CO 2 performance. In this work, BiOBr was hybridized with Ni-MOF, it shows that the E ads of BiOBr decreases from −0.36 eV to −1.73 eV, and the Gibbs free energy of CO 2 adsorption decreases from 0.12 eV to −1.25 eV. In addition, the PL and TPR results reveal that the hybridization strategy accelerates the electron-hole separation rates. The CO evolution of BiOBr/Ni-MOF is 121.8 μmol g−1 h−1 when the amount of Ni-MOF is 15%, which is 5 and 7.2 times higher than BiOBr and Ni-MOF, respectively. Briefly, the CO 2 adsorption and photogenerated carrier separation of inorganic materials can be improved by organic–inorganic hybridization strategy, which inspires a new direction for the design of high-performance catalysts. [ABSTRACT FROM AUTHOR]

In this work, we formed C 3 N 4 /Cu 2 O (CN/Cu 2 O) composite photocatalysts by growing Cu 2 O in situ on C 3 N 4 (CN) via oil bath method. The heterojunction between CN and Cu 2 O can broaden the light absorption range, enhance the light absorption, reduce the internal resistance to electron transfer and improve the efficiency of photogenerated electron-hole separation, thus enhancing the photocatalytic performance of carbon nitride. The photocatalytic performance of the synthesized CN/Cu 2 O composite photocatalysts was also tested. The test results showed that the best photocatalytic performance of CN/Cu 2 O-60 was achieved at 2.27 μmolg−1h−1 under 3 h xenon lamp irradiation, which was 8.5 and 5.7 times that of pure CN and pure Cu 2 O, respectively. [Display omitted] • CN/Cu 2 O improves electron-hole separation efficiency and spectral response range. • The photoreduction CO 2 performance reached 2.23 μmolg−1h−1, which is 8.3 times higher than that of pure C 3 N 4. • A possible mechanism of photoreduction CO 2 is proposed. [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]

• 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]

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]

A heterostructured ZnAl-LDH@ZIF-8 hybrid largely enhances its photocatalytic CO 2 reduction ability. [Display omitted] • A novel photocatalyst/adsorbent hybrid of ZnAl-LDH@ZIF-8 was prepared. • The hybrid showed a high visible-light-response activity and high selectivity for CO 2 reduction. • The mechanism on photocatalysis and adsorption of ZnAl-LDH@ZIF-8 hybrid was revealed. • The structure–activity relationship of ZnAl-LDH@ZIF-8 hybrid was studied in detail. • The photocatalytic performance of ZnAl-LDH@ZIF-8 hybrid was 7.0 times higher than ZnAl-LDH. Artificial photocatalytic technology is widely used to reduce atmospheric CO 2 and convert it into a series of available carbon containing fuels. Among a series of photocatalysts, LDH (layered double hydroxides) and ZIF (zeolitic imidazolate framework) materials have attracted interest of many researchers because of their special physical and chemical properties. In this work, we center on the technical problems of LDH and ZIF in photocatalytic CO 2 reduction process, we combined the respective advantages of LDH and ZIF materials to design a new heterostructured ZnAl-LDH@ZIF-8 hybrid photocatalyst/adsorbent, which had a wide range of visible light response, high activity and high selectivity. Through a series of structural characterizations, the results revealed that ZnAl-LDH as a catalyst was excited and produced photoelectric charge under the excitation of sunlight. Meanwhile, the CO 2 adsorbed on the catalyst surface was reduced to CO by photogenerated electrons which were migrated from ZnAl-LDH to ZIF-8 surface. The ZnAl-LDH@ZIF-8 hybrid showed a remarkable photocatalytic CO 2 conversion of 9.03 μmol·g−1·h−1 and a high selectivity of 97.77%. In addition, the effect on the excitation transfer of photoelectric charge and photocatalytic CO production of interaction between ZnAl-LDH and ZIF-8 were studied, and the relationships among catalyst compositions, surface structures, photoelectric properties, and catalytic performances were clarified. This research supplies a significant method for the construction and development of new type photocatalyst/adsorbent heterostructure, and provides new viewpoints and technical support for in-depth understanding of photocatalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]