2023 New's Items

Quantification of strain and its impact on the phase stabilization of all-inorganic cesium lead iodide perovskites

Le HKD
Yang P
2023

The high-temperature perovskite γ-phase of CsPbI3 readily undergoes phase transition at ambient conditions to a low-temperature non-perovskite δ-phase with a poorer optoelectronic performance, thus hindering commercialization of these materials in photovoltaics. Here, we present the epitaxial growth of CsPbI3 nanoplates on muscovite mica single-crystal substrates and demonstrate that the high-temperature phase stability of these nanoplates is enhanced by a strained interface. Strain is measured as a function of nanoplate thickness...

Photochemical Diodes for Simultaneous Bias-Free Glycerol Valorization and Hydrogen Evolution

Lin JA
Roh I
Yang P
2023

Artificial photosynthesis offers a route to producing clean fuel energy. However, the large thermodynamic requirement for water splitting along with the corresponding sluggish kinetics for the oxygen evolution reaction (OER) limits its current practical application. Here, we offer an alternative approach by replacing the OER with the glycerol oxidation reaction (GOR) for value-added chemicals. By using a Si photoanode, a low GOR onset potential of −0.05 V vs RHE and a photocurrent density of 10 mA/cm2 at 0.5 V vs RHE can be reached. Coupled with a Si...

Chemical and Structural Evolution of AgCu Catalysts in Electrochemical CO2 Reduction

Chen PC
Yang P
2023

Silver–copper (AgCu) bimetallic catalysts hold great potential for electrochemical carbon dioxide reduction reaction (CO2RR), which is a promising way to realize the goal of carbon neutrality. Although a wide variety of AgCu catalysts have been developed so far, it is relatively less explored how these AgCu catalysts evolve during CO2RR. The absence of insights into their stability makes the dynamic catalytic sites elusive and hampers the design of AgCu catalysts in a rational manner. Here, we synthesized intermixed and phase-...

Thermally driven phase transition of halide perovskites revealed by big data-powered in situ electron microscopy

Luo X
Yu Y
Yang P
2023

Halide perovskites are promising light-absorbing materials for high-efficiency solar cells, while the crystalline phase of halide perovskites may influence the device’s efficiency and stability. In this work, we investigated the thermally driven phase transition of perovskite (CsPbIxBr3−x), which was confirmed by electron diffraction and high-resolution transmission electron microscopy results. CsPbIxBr3−x transitioned from δ phase to α phase when heated, and the γ phase was obtained when the sample was cooled down. The γ phase was stable as long as it was isolated from humidity and...

Benzyl Alcohol Photo-oxidation Based on Molecular Electronic Transitions in Metal Halide Perovskites

Jin J
Yang P
2023

Vacancy ordered double perovskites Cs2Te(IV)X6 have been found to exhibit molecule-like electronic behavior when X is Cl– or Br– due to the zero-dimensional (0D) nature of their octahedral units. Electronically isolated building blocks, the [TeBr6]2– ionic octahedron, serve as the fundamental electronic unit of the Cs2TeBr6 solid. Herein, a detailed understanding of the Cs...

Operando Electrochemical Liquid-Cell Scanning Transmission Electron Microscopy (EC-STEM) Studies of Evolving Cu Nanocatalysts for CO2 Electroreduction

Yang Y
Yang P
2023

The design and synthesis of nanocatalysts with well-defined sizes, compositions, and structures have revolutionized our accessibility to tunable catalyst activity and selectivity for a variety of energy-related electrochemical reactions. Nonetheless, establishing structure-(re)activity correlations requires the understanding of the dynamic evolution of pristine nanocatalysts and the identification of their active states under operating conditions. We previously communicated the operando observation of Cu nanocatalysts evolving into active metallic Cu nanograins for CO2...

Direct Observation of Transient Structural Dynamics of Atomically Thin Halide Perovskite Nanowires

Gao M
Yang P
2023

Halide perovskite is a unique dynamical system, whose structural and chemical processes happening across different timescales have significant impact on its physical properties and device-level performance. However, due to its intrinsic instability, real-time investigation of the structure dynamics of halide perovskite is challenging, which hinders the systematic understanding of the chemical processes in the synthesis, phase transition, and degradation of halide perovskite. Here, we show that atomically thin carbon materials can stabilize ultrathin halide perovskite nanostructures...

Octahedral Distortion and Excitonic Behavior of Cs3Bi2Br9 Halide Perovskite at Low Temperature

Jin J
Yang P
2023

The metal halide ionic octahedron, represented as [MX6]n− (M = metal cation, X = halide anion), serves as the basic structural unit in halide perovskites and plays a crucial role in determining their optoelectronic and chemical properties. Thus, it is possible to correlate the responses of metal halide perovskites to various environmental stimuli with the dynamic behaviors of the [MX6]n− octahedra. In this study, with the temperature-dependent single-crystal X ray diffraction (...

Nanowire photochemical diodes for artificial photosynthesis

Andrei V
Roh I
Yang P
2023

Artificial photosynthesis can provide a solution to our current energy needs by converting small molecules such as water or carbon dioxide into useful fuels. This can be accomplished using photochemical diodes, which interface two complementary light absorbers with suitable electrocatalysts. Nanowire semiconductors provide unique advantages in terms of light absorption and catalytic activity, yet great control is required to integrate them for overall fuel production. In this review, we journey across the progress in nanowire photoelectrochemistry (PEC) over the past two decades,...

Operando studies reveal active Cu nanograins for CO2 electroreduction

Yang Y
Yang P
2023

Carbon dioxide electroreduction facilitates the sustainable synthesis of fuels and chemicals1. Although Cu enables CO2-to-multicarbon product (C2+) conversion, the nature of the active sites under operating conditions remains elusive...