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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]

Cost-effective CO 2 conversion to value-added products remains a great challenge until present. Here, we have discovered that the ethylenediamine (EDA) assisted preparation of Ni/CeO 2 catalyst remarkably promotes the CO 2 methanation performance at low temperatures. The Ni/CeO 2 -EDA catalyst exhibits a CO 2 conversion efficiency of 84% and a CH 4 selectivity of 98% at 225 °C, and no visible decline of CO 2 conversion is observed even after 70h of continuous reaction. The involvement of EDA is shown to effectively result in a more uniform distribution of Ni species, coupled with a reduction in particle size. In addition, the smaller particle size of Ni results in a rapid dissociative adsorption of hydrogen and H 2 spillover. Accordingly, oxygen vacancies on the CeO 2 surface are created and adequate H atoms are engendered for CO 2 hydrogenation. Furthermore, both the formate and CO pathways occur simultaneously on the Ni/CeO 2 -EDA catalyst, enhancing the low-temperature methanation activity. Herein, the EDA-assisted strategy provides an effective methodology in terms of well-dispersion and highly active catalysts for low-temperature CO 2 methanation. [Display omitted] • The addition of ethylenediamine promotes the Ni dispersion and CO 2 methanation activity on Ni/CeO 2. • Ni/CeO 2 -EDA catalyst presents 84% CO 2 conversion and 98% CH 4 selectivity at 225 °C. • The well-dispersion Ni particles facilitates a rapid dissociative adsorption of hydrogen and H 2 spillover. • The formate and CO route path way occurs over Ni/CeO 2 -EDA catalyst in parallel. [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]

The application of metal catalysis has gained prominence as a study area in recent years. In this work, we use adsorptive reduction and calcination to create Au–Pd alloy catalysts on COCN-2 with varying metal loadings. The plasma resonance effect of the alloys increases the photoresponse of the catalysts, and the engineering of nitrogen defects strengthens the strong bonds between Au–Pd alloy particles and carbon nitride graphite, optimizing the electronic structure, encouraging electron-directed migration, and increasing the efficiency of the reduction reaction. As a result, the efficiency of hydrogen generation by the Au–Pd 0.6 /COCN-2 catalyst is 5.089 mmol g−1 h−1, which is 2367 times higher than that of the g-C 3 N 4 catalyst. Our findings highlight the crucial part that flaws play in strengthening the strong bonds that exist between the metal and the support, which enhances photocatalytic hydrogen generation. This work offers insightful information about creating effective photocatalysts. • A series of Au–Pd/COCN catalysts were prepared via a facile method. • The performance of Au–Pd 0.6 /COCN-2 reached 5.089 mmol g−1 h−1, which is 2367 times higher than the pristine g-C 3 N 4. • A series of investigations were conducted to reveal the mechanism. [ABSTRACT FROM AUTHOR]

In this work, g-C 3 N 4 (U 1 W 1 –CNS) were prepared by calcination and Cu, B co-modified U 1 W 1 –CNS (Cu, B–CNS) was successfully fabricated by cryo-ultrasonic loading. B doping formed the unfavourable sub-centers and the Cu loading forms the electron-rich centre, which enhances the built-in electric field on the surface of U 1 W 1 –CNS. Hence, the 0.03Cu, 0.05B–CNS record a superior photocatalytic performance the hydrogen production rate reached to 1067 umolg−1h−1, which was 152, 10 and 1.67 times higher than that of U 1 W 1 –CNS (7 μmolg−1h−1), BCN (104 μmolg−1h−1) and 0.03Cu–CNS (638 μmolg−1h−1), respectively. This research provides new ideas for the design of U 1 W 1 –CNS photocatalyst with high performance photocatalytic hydrogen evolution. • Cu and B co-modification enhanced IEF, which improved the separation efficiency of photogenerated carriers. • The hydrogen evolution reached 1067 μmolg−1h−1, which is 152 times higher than U 1 W 1 –CNS. • A possible mechanism of hydrogen evolution is proposed. [ABSTRACT FROM AUTHOR]

At present, heterogeneous mercury-free catalysts are suffering from rapid deactivation caused by reduction or aggregation/growth of copper particle during preparation and reaction. Here, a high-performance and long-lived catalysts with activated carbon supported copper-ionic liquid system (Cu-xIL/AC, x is the molar ratio of IL and Cu) was prepared by wet impregnation method for the hydration of acetylene to acetaldehyde. Over the optimal Cu-1.5IL/AC catalyst, the acetylene conversion of 96.8% and acetaldehyde selectivity of 87.1% could still be obtained at 20 h (T = 240 °C, GHSV C2H2 = 90 h−1 and V H2O /V C2H2 = 1.15). The experimental results indicated that Cu species were embedded in ionic liquid (IL) and the interaction and synergistic effect between metal ions and IL guaranteed high and stable dispersion of active species on the host and suppress the reduction of active Cu specie, which are mainly responsible for the excellent catalytic property. The findings highlight the contribution of ILs in heterogeneous catalytic reaction and supply a promising industrial application of Cu-1.5IL/AC catalyst in acetylene hydration. • Supported ionic liquid catalysis (SILC) prepared by the wet impregnation method. • Cu-xIL/AC catalysts show higher selectivity formation of acetaldehyde (>90%). • Cu-1.5IL/AC catalyst was effective against the reduction of Cu particle. • Strong metal - Ionic liquid interaction effect provided small Cu particles. [ABSTRACT FROM AUTHOR]

Copper species have been extensively researched as effective cocatalysts for hydrogen evolution because of their inexpensive nature when compared to Pt. In this work, we have successfully loaded Cu nanoparticles highly dispersed on the surface of ZnIn 2 S 4 (ZIS) by an always simple low-temperature vacuum reduction method, which significantly improved the separation efficiency of photogenerated carriers. According to the transient photocurrent (TPR) and PL results, when the mass fraction of Cu is 0.6%, the maximum photocurrent density is approximately 0.55 μA/cm2, which is 2.75 times that of ZIS. And the separation efficiency of the photogenerated carriers is the fastest at this point. Simultaneously, under visible light and with a Cu loading of 0.6% in the Cu/ZnIn 2 S 4 (Cu/ZIS) composite material, the efficiency of hydrogen production is 6.56 times greater than that of pure ZIS, ultimately achieving an optimal value of 4.66 mmol/g/h. This study provides a new method for the preparation of photocatalysts with a high efficiency of electron-hole separation. [Display omitted] • Cu/ZIS improves electron-hole separation efficiency and spectral response range. • The photocatalytic hydrogen production reached 4.66 μmol−1h−1, which is 6.56 times that of pure ZIS. • A possible mechanism of photocatalytic hydrogen production is proposed. • A completely new method for low-temperature vacuum nonnoble metal deposition is proposed. [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]

Electrocatalysts with high efficiency are needed for the electrolysis of water in the OER and HER applications. This study investigated the use of ZnCo-ZIF as a precursor for synthesizing electrocatalysts with high specific surface area carbon. By bonding and dezincifying the ZnCo-ZIF at high temperatures, high specific surface area carbon was obtained. Additionally, selenium was introduced to the material to grow CoSe 2 nanowires, which showed excellent electrocatalytic activity. The CoSe 2 -600 sample, synthesized at 600 °C, exhibited the best electrocatalytic activity among the prepared samples. CoSe 2 -600 samples synthesized at 600 °C showed the best electrocatalytic activity. The study opens up a new direction for regulating selenium doping to improve the active specific surface area and electrocatalytic activity of materials, so as to enrich the types of electrocatalytic materials. These findings provide technical support for energy storage of doped carbon-based electrocatalysts. The study contributes to the development of high-efficiency electrocatalysts for water electrolysis, with potential applications in hydrogen production and other related fields. • ZnCo-ZIF was used as a precursor to synthesize high specific surface area carbon electrocatalysts for water electrolysis. • By introducing selenium to the material, CoSe 2 nanowires with excellent electrocatalytic activity were grown. • The CoSe 2 -600 sample synthesized at 600 °C exhibited the best electrocatalytic activity among the prepared samples. [ABSTRACT FROM AUTHOR]

Photogenerated electron-hole separation and transfer and band gap modulation are the main reasons for the performance of semiconductor catalysts. These problems can be effectively solved by the proper use of co-catalysts. However, the current co-catalysts are generally noble metal co-catalysts, which cannot be used industrially because of their high cost. Therefore, it is important to use non-noble metal co-catalyst to solve these problems. In this study, MoO 2 with localized surface plasmon resonance (LSPR) effect loaded onto ZnIn 2 S 4 (ZIS) by primary hydrothermal method and structured to form type II heterojunctions. The formation of the heterojunctions not only tunes the band gap to improve the light absorption intensity, but also reduces the charge transfer resistance and promotes electron-hole directed movement to improve the electron-hole separation efficiency. The tuning of the band gap and the increase in the electron-hole separation rate lead to improved performance of all ZIS/MoO 2 heterojunctions under visible light (λ ≥ 420 nm). Among them, ZIS/MoO 2 -4% has the best photocatalytic performance of 2.757 mmol g−1 h−1, which is 3.75 times higher than that of pure ZIS (0.736 mmol g−1 h−1). This study provides a new strategy for the preparation of high performance catalysts without precious metals. • ZnIn 2 S 4 /MoO 2 was prepared by hydrothermal solvothermal method. • The best hydrogen production of ZnIn 2 S 4 /MoO 2 under visible light was 2.801 mmolg−1h−1. • ZnIn 2 S 4 /MoO 2 broadens the visible light response and enhances the electron-hole separation. [ABSTRACT FROM AUTHOR]

One key challenge in photocatalytic hydrogen production is how to construct high-performance photocatalyst. Covalent triazine framework (CTF) based polymers as photocatalysts show great application potential because of their good photocatalytic activity, high chemical stability, tunable electronic and optical properties, and easy synthesis process. In this paper, we designed the ternary Z-scheme heterojunction Au@TiO 2 -X%TrTh based on CTF polymer TrTh, TiO 2 and Au nanoparticle, which exhibit higher photocatalytic hydrogen production rate compared with the corresponding binary heterojunction Au@TiO 2 and TiO 2 -12%TrTh. The results of photocatalytic hydrogen production show that the optimized Au@TiO 2 -12%TrTh has a remarkable hydrogen production rate of 4288.54 μmol g−1 h−1, which is about 312.3 times of Au@TiO 2 and 9.1 times of the TiO 2 -12%TrTh. The enhanced hydrogen production activity of the ternary heterojunction comes from the local surface plasmonic resonance effect of Au nanoparticle, lower recombination efficiency of photogenerated electron-holes pairs and Z-scheme electron transfer pathway of Au@TiO 2 -12%TrTh. The work provides a new strategy for designing efficient and practical photocatalyst. [Display omitted] • Ternary Au@TiO 2 -X%TrTh heterojunctions are prepared for hydrogen evolution. • The introduction of polymer TrTh extends the absorption of visible light of the composites. • The Au nanoparticles can accelerate the photoinduced carrier migration. • A Z-Scheme electron flow direction was purposed for the heterojunctions. • The ternary composites show excellent photocatalytic performances. [ABSTRACT FROM AUTHOR]