Photocatalytic Hydrogen Peroxide Production by a Mixed Ligand-Functionalized Uranyl–Organic Framework
Ontology highlight
ABSTRACT:
SUBMITTER: Wang X
PROVIDER: S-EPMC11307301 | biostudies-literature | 2024 Jul
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Photocatalytic hydrogen production using stable metal-organic frameworks (MOFs), especially the titanium-based MOFs (Ti-MOFs) as photocatalysts is one of the most promising solutions to solve the energy crisis. However, due to the high reactivity and harsh synthetic conditions, only a limited number of Ti-MOFs have been reported so far. Herein, we synthesized a new amino-functionalized Ti-MOFs, named NH2-ZSTU-2 (ZSTU stands for Zhejiang Sci-Tech University), for photocatalytic hydrogen production under visible light irradiation. The NH2-ZSTU-2 was synthesized by a facile solvothermal method, composed of 2,4,6-tri(4-carboxyphenylphenyl)-aniline (NH2-BTB) triangular linker and infinite Ti-oxo chains. The structure and photoelectrochemical properties of NH2-ZSTU-2 were fully studied by powder X-ray diffraction, scanning electron microscope, nitro sorption isotherms, solid-state diffuse reflectance absorption spectra, and Mott-Schottky measurements, etc., which conclude that NH2-ZSTU-2 was favorable for photocatalytic hydrogen production. Benefitting from those structural features, NH2-ZSTU-2 showed steady hydrogen production rate under visible light irradiation with average photocatalytic H2 yields of 431.45 μmol·g-1·h-1 with triethanolamine and Pt as sacrificial agent and cocatalyst, respectively, which is almost 2.5 times higher than that of its counterpart ZSTU-2. The stability and proposed photocatalysis mechanism were also discussed. This work paves the way to design Ti-MOFs for photocatalysis.
| S-EPMC9268624 | biostudies-literature
Project description:Photocatalysis provides a sustainable and environment-friendly strategy to produce H2O2, yet the catalytic efficiency of H2O2 overall photosynthesis (O2 + 2H2O → 2H2O2) needs to be further improved, especially in the absence of additional cocatalysts, photosensitizers and sacrificial agents. Here we find that hydrogen-bonded organic frameworks can serve as photocatalysts for H2O2 overall photosynthesis under the above-mentioned conditions. Specifically, we constructed a donor-acceptor hydrogen-bonded organic framework that exhibits a high photocatalytic activity for H2O2 overall photosynthesis, with a production rate of 681.2 μmol g-1 h-1. The control experiments and theoretical calculation revealed that the hydrogen-bonded organic frameworks with donor-acceptor structures can not only accelerate the charge separation and transfer but also optimize the reaction pathways, which significantly boosts the photocatalytic efficiency in H2O2 overall photosynthesis. This work provides insights into the design and development of efficient photocatalysts for overall H2O2 photosynthesis.
| S-EPMC11897405 | biostudies-literature
Project description:A high-throughput sonochemical synthesis and testing strategy was developed to discover covalent organic frameworks (COFs) for photocatalysis. In total, 76 conjugated polymers were synthesized, including 60 crystalline COFs of which 18 were previously unreported. These COFs were then screened for photocatalytic hydrogen peroxide (H2O2) production using water and oxygen. One of these COFs, sonoCOF-F2, was found to be an excellent photocatalyst for photocatalytic H2O2 production even in the absence of sacrificial donors. However, after long-term photocatalytic tests (96 h), the imine sonoCOF-F2 transformed into an amide-linked COF with reduced crystallinity and loss of electronic conjugation, decreasing the photocatalytic activity. When benzyl alcohol was introduced to form a two-phase catalytic system, the photostability of sonoCOF-F2 was greatly enhanced, leading to stable H2O2 production for at least 1 week.
| S-EPMC9185744 | biostudies-literature
Project description:The direct utilization of solar energy for the artificial photosynthesis of hydrogen peroxide (H2O2) provides a reliable approach for producing this high-value green oxidant. Here we report on the utility of high-entropy oxide (HEO) semiconductor as an all-in-one photocatalyst for visible light-driven H2O2 production directly from H2O and atmospheric O2 without the need of any additional cocatalysts or sacrificial agents. This high-entropy photocatalyst contains eight earth-abundant metal elements (Ti/V/Cr/Nb/Mo/W/Al/Cu) homogeneously arranged within a single rutile phase, and the intrinsic chemical complexity along with the presence of a high density of oxygen vacancies endow high-entropy photocatalyst with distinct broadband light harvesting capability. An efficient H2O2 production rate with an apparent quantum yield of 38.8% at 550 nm can be achieved. The high-entropy photocatalyst can be readily assembled into floating artificial leaves for sustained on-site production of H2O2 from open water resources under natural sunlight irradiation.
| S-EPMC11532407 | biostudies-literature
Project description:Photocatalytic hydrogen production has been considered a promising approach to obtain green hydrogen energy. Crystalline porous materials have arisen as key photocatalysts for efficient hydrogen production. Here, we report a strategy to in situ photodeposit platinum clusters as cocatalyst on a covalent organic framework, which makes it an efficient photocatalyst for light-driven hydrogen evolution. Periodically dispersed adsorption sites of platinum species are constructed by introducing adjacent hydroxyl group and imine-N in the region of the covalent organic framework structural unit where photogenerated electrons converge, leading to the in situ reduction of the adsorbed platinum species into metal clusters by photogenerated electrons. The widespread platinum clusters on the covalent organic framework expose large active surface and greatly facilitate the electron transfer, finally contributing to a high photocatalytic hydrogen evolution rate of 42432 μmol g-1 h-1 at 1 wt% platinum loading. This work provides a direction for structural design on covalent organic frameworks to precisely manipulate cocatalyst morphologies and positions at the atomic level for developing efficient photocatalysts.
| S-EPMC8924255 | biostudies-literature
Project description:Developing highly active, recyclable, and inexpensive photocatalysts for hydrogen evolution reaction (HER) under visible light is significant for the direct conversion of solar energy into chemical fuels for various green energy applications. For such applications, it is very challenging but vitally important for a photocatalyst to simultaneously enhance the visible-light absorption and suppress photogenerated electron-hole recombination, while also to maintain high stability and recyclability. Herein, a metal-organic framework (MOF)-templated strategy has been developed to prepare heterostructured nanocatalysts with superior photocatalytic HER activity. Very uniquely, the synthesized photocatalytic materials can be recycled easily after use to restore the initial photocatalytic activity. It is shown that by controlling the calcination temperature and time with MOF-5 as a host and guest thioacetamide as a sulfur source, the chemical compositions of the formed heterojunctions of ZnO/ZnS can be tuned to further enhance the visible-light absorption and photocatalytic activity. The nanoscale heterojunction ZnO/ZnS structural feature serves to reduce the average free path of charge carriers and improve the charge separation efficiency, thus leading to significantly enhanced HER activity under visible-light irradiation (λ > 420 nm) with high stability and recyclability without any cocatalyst.
| S-EPMC5908348 | biostudies-literature
Project description:On-site peroxide generation via electrochemical reduction is gaining tremendous attention due to its importance in many fields, including water treatment technologies. Oxidized graphitic carbon-based materials have been recently proposed as an alternative to metal-based catalysts in the electrochemical oxygen reduction reaction (ORR), and in this work we unravel the role of C=O groups in graphene towards sustainable peroxide formation. We demonstrate a versatile single-step electrochemical exfoliation of graphite to graphene with a controllable degree of oxygen functionalities and thickness, leading to the formation of large quantities of functionalized graphene with tunable rate parameters, such as the rate constant and exchange current density. Higher oxygen-containing exfoliated graphene is known to undergo a two-electron reduction path in ORR having an efficiency of about 80 ± 2% even at high overpotential. Bulk production of H2O2 via electrolysis was also demonstrated at low potential (0.358 mV vs RHE), yielding ≈34 mg/L peroxide with highly functionalized (≈23 atom %) graphene and ≈16 g/L with low functionalized (≈13 atom %) graphene, which is on par with the peroxide production using state-of-the-art precious-metal-based catalysts. Hence this method opens a new scheme for the single-step large-scale production of functionalized carbon-based catalysts (yield ≈45% by weight) that have varying functionalities and can deliver peroxide via the electrochemical ORR process.
| S-EPMC7082696 | biostudies-literature
Project description:Facet-dependent catalytic activity of hard materials such as metals and metal oxides is well recognized in previous works. However, it has rarely been established for metal-organic frameworks (MOFs), possibly because the soft crystals of MOFs are conceptually different from the hard solids. In this work, the surface structure of the MOF NH2-MIL-125(Ti) has been investigated by density functional theory (DFT) calculations for the first time. These calculations predict that the {110} facet has a surface energy of 1.18 J m-2, which is superior to those of the {001}, {100} and {111} facets. This difference can be attributed to the larger percentage of exposed metal clusters, which can act as active sites in catalysis. Thus, we have devised and successfully obtained a series of nanoscaled NH2-MIL-125(Ti) MOFs with controlled facets both experimentally and theoretically. The sample containing the {110} facet exhibits the highest photocatalytic hydrogen production activity and apparent quantum yield, which are approximately three times those of the sample with a dominant {111} facet.
| S-EPMC6509995 | biostudies-literature
Project description:Nanosizing confers unique functions in materials such as graphene and quantum dots. Here, we present two nanoscale-covalent organic frameworks (nano-COFs) that exhibit exceptionally high activity for photocatalytic hydrogen production that results from their size and morphology. Compared to bulk analogues, the downsizing of COFs crystals using surfactants provides greatly improved water dispersibility and light-harvesting properties. One of these nano-COFs shows a hydrogen evolution rate of 392.0 mmol g-1 h-1 (33.3 μmol h-1), which is one of the highest mass-normalized rates reported for a COF or any other organic photocatalysts. A reverse concentration-dependent photocatalytic phenomenon is observed, whereby a higher photocatalytic activity is found at a lower catalyst concentration. These materials also show a molecule-like excitonic nature, as studied by photoluminescence and transient absorption spectroscopy, which is again a function of their nanoscale dimensions. This charts a new path to highly efficient organic photocatalysts for solar fuel production.
| S-EPMC11294449 | biostudies-literature
Project description:Developing efficient artificial photocatalysts for the biomimetic photocatalytic production of molecular materials, including medicines and clean energy carriers, remains a fundamentally and technologically essential challenge. Hydrogen peroxide is widely used in chemical synthesis, medical disinfection, and clean energy. However, the current industrial production, predominantly by anthraquinone oxidation, suffers from hefty energy penalties and toxic byproducts. Herein, we report the efficient photocatalytic production of hydrogen peroxide by protonation-induced dispersible porous polymers with good charge-carrier transport properties. Significant photocatalytic hydrogen peroxide generation occurs under ambient conditions at an unprecedented rate of 23.7 mmol g-1 h-1 and an apparent quantum efficiency of 11.3% at 450 nm. Combined simulations and spectroscopies indicate that sub-picosecond ultrafast electron "localization" from both free carriers and exciton states at the catalytic reaction centers underlie the remarkable photocatalytic performance of the dispersible porous polymers.
| S-EPMC10613291 | biostudies-literature