Photocatalytic ethylene production by oxidative dehydrogenation of ethane with dioxygen on ZnO-supported PdZn intermetallic nanoparticles

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Янв. 26, 2024

Abstract The selective oxidative dehydrogenation of ethane (ODHE) is attracting increasing attention as a method for ethylene production. Typically, thermocatalysts operating at high temperatures are needed C–H activation in ethane. In this study, we describe low temperature ( < 140 °C) photocatalytic route ODHE, using O 2 the oxidant. A photocatalyst containing PdZn intermetallic nanoparticles supported on ZnO prepared, affording an production rate 46.4 mmol g –1 h with 92.6% selectivity under 365 nm irradiation. When employ simulated shale gas feed, ODHE system achieves nearly 20% conversion while maintaining about 87%. robust interface between and support plays crucial role through photo-assisted Mars-van Krevelen mechanism, followed by rapid lattice oxygen replenishment to complete reaction cycle. Our findings demonstrate that promising alkane-to-alkene conversions mild conditions.

Язык: Английский

---

Rapid Interlayer Charge Separation and Extended Carrier Lifetimes due to Spontaneous Symmetry Breaking in Organic and Mixed Organic–Inorganic Dion–Jacobson Perovskites

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(9), С. 5297 - 5309

Опубликована: Фев. 24, 2023

Promising alternatives to three-dimensional perovskites, two-dimensional (2D) layered metal halide perovskites have proven their potential in optoelectronic applications due improved photo- and chemical stability. Nevertheless, photovoltaic devices based on 2D suffer from poor efficiency owing unfavorable charge carrier dynamics energy losses. Focusing the Dion-Jacobson perovskite phase that is rapidly rising popularity, we demonstrate doping of complementary cations into 3-(aminomethyl)piperidinium accelerates spontaneous separation slows down recombination, both factors improving performance. Employing ab initio nonadiabatic (NA) molecular combined with time-dependent density functional theory, cesium broadens bandgap by 0.4 eV breaks structural symmetry. Assisted thermal fluctuations, symmetry breaking helps localize electrons holes different layers activates additional vibrational modes. As a result, accelerated. Simultaneously, lifetime grows shortened coherence time between ground excited states. The established relationships composition provide guidelines toward future material discovery design solar cells.

Язык: Английский

---

Minimized optical/electrical energy loss for 25.1% Monolithic perovskite/organic tandem solar cells

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Фев. 19, 2025

Perovskite/organic tandem solar cells (PO-TSCs) exploit the advantages of cost-effective fabrication, orthogonal solvent processing for perovskite and organic absorber layers, compatibility with low-temperature, high-throughput deposition techniques. However, their performance remains hampered by energy losses subcells interconnecting layers (ICLs). Here, an loss management strategy PO-TSCs is proposed, focusing on simultaneous regulation defect states in front reduction optical electrical ICL. The synergistic effect hydrogen bonding coordination interactions between pyridinium bromide perbromide layer effectively mitigates ion migration, thereby minimizing losses. Meanwhile, optimized V2O5-based ICL structure not only demonstrates excellent transmissivity near-infrared photons but also allows barrier-free extraction charge carriers. Such can provide a low-loss interface, facilitating light within bulk heterojunction, which balances current rear subcells. Taken together, resulting deliver power conversion efficiency 25.1% high open-circuit voltage 2.10 V. perovskite/organic authors introduce into perovskites employ ICL, achieving maximum devices.

Язык: Английский

---

Nuclear Quantum Effects Prolong Charge Carrier Lifetimes in Hybrid Organic–Inorganic Perovskites

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(25), С. 14112 - 14123

Опубликована: Июнь 19, 2023

Hybrid organic-inorganic perovskites (HOIPs) contain light hydrogen atoms that exhibit significant nuclear quantum effects (NQEs). We demonstrate NQEs have a strong effect on HOIP geometry and electron-vibrational dynamics at both low ambient temperatures, even though charges in HOIPs reside heavy elements. By combining ring-polymer molecular (MD) ab initio MD with nonadiabatic time-dependent density functional theory focusing the most studied tetragonal CH3NH3PbI3, we show increase disorder thermal fluctuations through coupling of inorganic cations to lattice. The additional induces charge localization decreases electron-hole interactions. As result, nonradiative carrier lifetimes are extended by factor 3 160 K 1/3 330 K. radiative increased 40% temperatures. fundamental band gap 0.10 0.03 eV K, respectively. enhancing atomic motions introducing new vibrational modes, strengthen Decoherence, determined elastic scattering, accelerates almost 2 due NQEs. However, coupling, driving recombination, because it is more sensitive structural distortions than HOIPs. This study demonstrates, for first time, should be considered achieve an accurate understanding evolution provides important insights design related materials optoelectronic applications.

Язык: Английский

---

Tuning Octahedral Tilting by Doping to Prevent Detrimental Phase Transition and Extend Carrier Lifetime in Organometallic Perovskites

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(9), С. 5393 - 5399

Опубликована: Фев. 21, 2023

As one of the most promising materials for next-generation solar cells, organometallic perovskites have attracted substantial fundamental and applied interest. Using first-principles quantum dynamics calculations, we show that octahedral tilting plays an important role in stabilizing perovskite structures extending carrier lifetimes. Doping material with (K, Rb, Cs) ions at A-site enhances stability system relative to unfavorable phases. The doped is maximized uniform distribution dopants. Conversely, aggregation dopants inhibits associated stabilization. simulations also indicate enhanced tilting, band gap increases, coherence time nonadiabatic coupling decrease, lifetimes are thus extended. Our theoretical work uncovers quantifies heteroatom-doping stabilization mechanisms, opening up new avenues enhancing optical performance perovskites.

Язык: Английский

---

Origin of Phase Transitions in Inorganic Lead Halide Perovskites: Interplay between Harmonic and Anharmonic Vibrations

ACS Energy Letters, Год журнала: 2023, Номер 8(7), С. 3016 - 3024

Опубликована: Июнь 16, 2023

Inorganic lead halide perovskites (ILHPs) exhibit a series of phase transitions, and stabilization the phases with desirable optoelectronic properties remains major challenge. However, intrinsic origins structural instabilities in CsPbX3 (X = Br, I) are still elusive. Herein, important role harmonic anharmonic vibrations influencing thermodynamic fluctuations ILHPs was revealed, through combined lattice dynamics multiphonon theory calculations, verified by diffraction experiments. Our results demonstrate that transition between δ- γ-CsPbI3 is driven vibrations, unveiling mysterious mechanism for stabilizing via applying strain. Moreover, successive transitions from α- to β- γ-phases vibrations. These strongly coherent phonon diffuse scattering, substantially affecting thermal conductivity carrier relaxation. This work provides guidelines maintaining favorable ILHP delicately manipulating their dynamics.

Язык: Английский

---

Twist Angle-Dependent Intervalley Charge Carrier Transfer and Recombination in Bilayer WS₂

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(41), С. 22826 - 22835

Опубликована: Окт. 5, 2023

A twist angle at a van der Waals junction provides handle to tune its optoelectronic properties for variety of applications, and comprehensive understanding how the modulates electronic structure, interlayer coupling, carrier dynamics is needed. We employ time-dependent density functional theory nonadiabatic molecular elucidate angle-dependent intervalley transfer recombination in bilayer WS2. Repulsion between S atoms twisted configurations weakens increases distance, softens layer breathing modes. Twisting has minor influence on K valleys while it lowers Γ raises Q because their wave functions are delocalized layers. Consequently, reduced energy gaps accelerate hole structures. Intervalley electron proceeds nearly an order magnitude faster than transfer. The more localized values larger bandgaps result smaller couplings recombination, making 3-4 times slower high-symmetry B2g breathing, E2g in-plane, A1g out-of-plane modes most active during recombination. extended lifetimes junctions favorable device performance.

Язык: Английский

---

Halide Vacancies Create No Charge Traps on Lead Halide Perovskite Surfaces but Can Generate Deep Traps in the Bulk

The Journal of Physical Chemistry Letters, Год журнала: 2023, Номер 14(26), С. 6028 - 6036

Опубликована: Июнь 23, 2023

Metal halide perovskites (MHPs) have attracted attention because of their high optoelectronic performance that is fundamentally rooted in the unusual properties MHP defects. By developing an ab initio-based machine-learning force field, we sample structural dynamics MHPs on a nanosecond time scale and show vacancies create midgap trap states bulk but not surface. Deep traps result from Pb-Pb dimers can form across vacancy only bulk. The required shortening distance by nearly 3 Å facilitated either charge trapping or 50 ps thermal fluctuations. large-scale deformations are possible soft. Halide surface no deep separate electrons holes, keeping charges mobile. This particularly favorable for quantum dots, which do require sophisticated passivation to emit light blink less than dots formed traditional inorganic semiconductors.

Язык: Английский

---

Organic-inorganic hybrid nature enables efficient and stable CsPbI3-based perovskite solar cells

Joule, Год журнала: 2023, Номер 7(12), С. 2905 - 2922

Опубликована: Ноя. 23, 2023

Язык: Английский

---

Compression Eliminates Charge Traps by Stabilizing Perovskite Grain Boundary Structures: An Ab Initio Analysis with Machine Learning Force Field

Chemistry of Materials, Год журнала: 2024, Номер 36(6), С. 2898 - 2906

Опубликована: Март 12, 2024

Grain boundaries (GBs) play an important role in determining the optoelectronic properties of perovskites, requiring atomistic understanding underlying mechanisms. Strain engineering has recently been employed perovskite solar cells, providing a novel perspective on GBs. Here, we theoretically investigate impact axial strain geometric and electronic common CsPbBr3 GB. We develop machine learning force field perform ab initio calculations to analyze behavior GB models with different strains nanosecond time scale. Our results demonstrate that compressing efficiently suppresses structural fluctuations eliminates trap states originating from large-scale distortions. The becomes more amorphous under compressive strain, which makes relationship between structure nonmonotonic. These can help clarify conflicts experiments.

Язык: Английский

---