Unraveling the dual defect sites in graphite carbon nitride for ultra-high photocatalytic H₂O₂ evolution

Energy & Environmental Science, Год журнала: 2022, Номер 15(2), С. 830 - 842

Опубликована: Янв. 1, 2022

The g-C 3 N 4 with dual defect sites exhibits excellent photocatalytic H 2 O generation activity and selectivity, the key role of each site in surface reaction mechanism is revealed.

Язык: Английский

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Piezo‐Photocatalysis over Metal–Organic Frameworks: Promoting Photocatalytic Activity by Piezoelectric Effect

Advanced Materials, Год журнала: 2021, Номер 33(51)

Опубликована: Окт. 13, 2021

The built-in electric field can be generated in the piezoelectric materials under mechanical stress. resulting effect is beneficial to charge separation photocatalysis. Meanwhile, stress usually gives rise accelerated mass transfer and enhanced catalytic activity. Unfortunately, it remains a challenge differentiate contribution of these two factors performance. Herein, for first time, isostructural metal-organic frameworks (MOFs), i.e., UiO-66-NH2 (Zr) (Hf), are adopted piezo-photocatalysis. Both MOFs, featuring same structures except diverse Zr/Hf-oxo clusters, possess distinctly different properties. Strikingly, (Hf) exhibits ≈2.2 times activity compared with that simultaneous light ultrasonic irradiation, though both MOFs display similar photocatalytic H2 production without irradiation. Given their pore features behaviors, difference unambiguously assignable effect. As result, contributions piezo-photocatalysis clearly distinguished owing stronger property (Hf).

Язык: Английский

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Cooperative Coupling of H₂O₂ Production and Organic Synthesis over a Floatable Polystyrene‐Sphere‐Supported TiO₂/Bi₂O₃ S‐Scheme Photocatalyst

Advanced Materials, Год журнала: 2022, Номер 34(38)

Опубликована: Авг. 9, 2022

Cooperative coupling of photocatalytic H2 O2 production with organic synthesis has an expansive perspective in converting solar energy into storable chemical energy. However, traditional powder photocatalysts suffer from severe agglomeration, limited light absorption, poor gas reactant accessibility, and reusable difficulty, which greatly hinders their large-scale application. Herein, floatable composite are synthesized by immobilizing hydrophobic TiO2 Bi2 O3 on lightweight polystyrene (PS) spheres via hydrothermal photodeposition methods. The not only transparent, but also upgrade the contact between reactants photocatalysts. Thus, step-scheme (S-scheme) /Bi2 photocatalyst exhibits a drastically enhanced yield 1.15 mm h-1 decent furfuryl alcohol conversion to furoic acid synchronously. Furthermore, S-scheme mechanism dynamics systematically investigated situ irradiated X-ray photoelectron spectroscopy femtosecond transient absorption spectrum analyses. In Fourier transform infrared density functional theory calculations reveal evolution. ingenious design furnishes insight maximizing reaction kinetics provides new route for highly efficient heterogeneous catalysis.

Язык: Английский

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Construction of Interfacial Electric Field via Dual‐Porphyrin Heterostructure Boosting Photocatalytic Hydrogen Evolution

Advanced Materials, Год журнала: 2021, Номер 34(3)

Опубликована: Ноя. 5, 2021

A dual-porphyrin heterostructure is successfully constructed by coupling tetrakis (4-carboxyphenyl) zinc porphyrin (ZnTCPP) with (4-hydroxyphenyl) (THPP). The high photocatalytic H2 evolution rate of 41.4 mmol h-1 g-1 obtained for ZnTCPP/THPP under full spectrum, which ≈5.1 and ≈17.0 times higher than that pure ZnTCPP THPP, respectively. significantly enhanced activity mainly attributed to the giant interfacial electric field formed between dual porphyrins, greatly facilitates efficient charge separation transfer. Meanwhile, similar conjugated structures porphyrins also provide proper interface match decrease defects, thus inhibiting recombination photoproduced carriers. By rationally combining appropriate band high-quality contact this work provides a fresh insight into construction improve performance.

Язык: Английский

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A Full‐Spectrum Porphyrin–Fullerene D–A Supramolecular Photocatalyst with Giant Built‐In Electric Field for Efficient Hydrogen Production

Advanced Materials, Год журнала: 2021, Номер 33(31)

Опубликована: Июль 8, 2021

Abstract A full‐spectrum (300–850 nm) responsive donor–acceptor (D–A) supramolecular photocatalyst tetraphenylporphinesulfonate/fullerene (TPPS/C 60 ) is successfully constructed. The theoretical spectral efficiency of TPPS/C as high 70%, offering the possibility full‐solar‐spectrum light harvesting. performs a highly efficient photocatalytic H 2 evolution rate 276.55 µmol h −1 (34.57 mmol g ), surpassing many reported organic photocatalysts. D–A structure effectively promotes electron transfer from TPPS to C , which beneficial reaction. Specifically, giant internal electric field in built via enhanced molecular dipole, dramatically charge separation (CS) by 2.35 times. Transient absorption spectra results show long‐lived CS state •+ –C •− structure, participation photogenerated electrons reduction Briefly, this work provides novel approach for designing high‐performance materials enhancing interfacial field.

Язык: Английский

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Optimizing Atomic Hydrogen Desorption of Sulfur‐Rich NiS_1+x Cocatalyst for Boosting Photocatalytic H₂ Evolution

Advanced Materials, Год журнала: 2021, Номер 34(6)

Опубликована: Ноя. 23, 2021

Low-cost transition-metal chalcogenides (MSx ) are demonstrated to be potential candidate cocatalyst for photocatalytic H2 generation. However, their -generation performance is limited by insufficient quantities of exposed sulfur (S) sites and strong bonding with adsorbed hydrogen atoms (SHads ). To address these issues, an efficient coupling strategy active-site-enriched regulation electronic structure modification active S developed rational design core-shell Au@NiS1+x nanostructured cocatalyst. In this case, the can skillfully fabricated synthesize modified TiO2 (denoted as /Au@NiS1+x a two-step route. Photocatalytic experiments exhibit that resulting (1.7:1.3) displays boosted rate 9616 µmol h-1 g-1 apparent quantum efficiency 46.0% at 365 nm, which 2.9 1.7 times over /NiS1+x /Au, respectively. situ/ex situ XPS characterization density functional theory calculations reveal free-electrons Au transfer sulfur-enriched NiS1+x induce generation electron-enriched Sδ- centers, boosts desorption Hads rapid formation via weakening SHads bonds. Hence, -mediated mechanism proposed. This work delivers universal simultaneously increasing site number optimizing binding strength between adsorbates.

Язык: Английский

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Perylenetetracarboxylic acid nanosheets with internal electric fields and anisotropic charge migration for photocatalytic hydrogen evolution

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Апрель 19, 2022

Abstract Highly efficient hydrogen evolution reactions carried out via photocatalysis using solar light remain a formidable challenge. Herein, perylenetetracarboxylic acid nanosheets with monolayer thickness of ~1.5 nm were synthesized and shown to be active photocatalysts production rates 118.9 mmol g −1 h . The carboxyl groups increased the intensity internal electric fields from perylene center border by 10.3 times promote charge-carrier separation. photogenerated electrons holes migrated edge plane, respectively, weaken recombination. Moreover, reduction potential increases −0.47 V −1.13 due decreased molecular conjugation enhances ability. In addition, created hydrophilic sites. This work provides strategy engineer structures future photocatalysts.

Язык: Английский

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Piezo‐Photocatalytic Synergy in BiFeO₃@COF Z‐Scheme Heterostructures for High‐Efficiency Overall Water Splitting

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(44)

Опубликована: Сен. 13, 2022

Solar-driven overall water splitting is an ideal way to generate renewable energy while still challenging. For the first time, this work combined covalent organic frameworks (COFs) and piezoelectric material by linkages form Z-scheme core@shell heterostructure for splitting. Benefiting from synergistic effect between polarized electric field photo-generated charges, as well precise adjustment of shell thickness, carrier separation utilization efficiency greatly improved. The optimal BiFeO3 @TpPa-1-COF photocatalyst revealed hydrogen (H2 ) oxygen (O2 production rates 1416.4 708.2 μmol h-1 g-1 under excitation ultrasonication coupled with light irradiation, which best performance among various piezo- COF-based photocatalysts. This provides a new sight practical application highly efficient photocatalytic

Язык: Английский

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Photocatalytic Z‐Scheme Overall Water Splitting: Recent Advances in Theory and Experiments

Advanced Materials, Год журнала: 2021, Номер 33(52)

Опубликована: Окт. 7, 2021

Abstract Photocatalytic water splitting is considered one of the most important and appealing approaches for production green H 2 to address global energy demand. The utmost possible form artificial photosynthesis a two‐step photoexcitation known as “Z‐scheme”, which mimics natural photosystem. This process solely relies on effective coupling suitable band positions semiconductors (SCs) redox mediators purpose catalyze surface chemical reactions significantly deter backward reaction. In recent years, Z‐scheme strategies their key role have been studied progressively through experimental approaches. addition, theoretical studies based density functional theory provided detailed insight into mechanistic aspects some breathtakingly complex problems associated with hydrogen evolution reaction oxygen this context, critical review gives an overview fundamentals photocatalysis, including both advancements in field photocatalytic splitting, suggests future perspectives.

Язык: Английский

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Mesoporous black TiO2/MoS2/Cu2S hierarchical tandem heterojunctions toward optimized photothermal-photocatalytic fuel production

Chemical Engineering Journal, Год журнала: 2021, Номер 427, С. 131830 - 131830

Опубликована: Авг. 15, 2021

Язык: Английский

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