Publications by authors named "Chun-Chih Chang"

Urea electrolysis can address pressing environmental concerns caused by urea-containing wastewater while realizing energy-saving hydrogen production. Highly efficient and affordable electrocatalysts are indispensable for realizing the great potential of this emerging technology. Among the numerous candidates, α-Ni(OH) has the merits of good electrocatalytic activity, adjustable heteroelement doping, and low cost; consequently, it has received tremendous attention in the electrolytic fields.

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The dynamic characterization of guest molecules in the metal-organic frameworks (MOFs) can always provide the insightful and inspiring information to facilitate the synthetic design of MOF materials from the bottom-up design of perspective. Herein, we present a series of atomistic molecular dynamics simulation for investigating the bipyridine dicarboxylate (bpydc) linker rotation effect on guest molecule adsorption with and without considering the transition metal (TM) chelation in MOF-253 materials. The simulated PXRD patterns of the various linker orientations present the challenge of distinguishing these structural varieties by the conventional crystalline spectroscopic measurements.

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Internet misinformation and government-sponsored disinformation campaigns have been criticized for their presumed/hypothesized role in worsening the coronavirus disease 2019 (COVID-19) pandemic. We hypothesize that these government-sponsored disinformation campaigns have been positively associated with infectious disease epidemics, including COVID-19, over the last two decades. By integrating global surveys from the Digital Society Project, Global Burden of Disease, and other data sources across 149 countries for the period 2001-2019, we examined the association between government-sponsored disinformation and the spread of respiratory infections before the COVID-19 outbreak.

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Background: Enhanced nonpharmaceutical interventions (NPIs) to prevent the Coronavirus Disease 2019 (COVID-19) have shown various levels of impact on common respiratory pathogens. We aimed to analyze the epidemiological changes seen in certain common respiratory viruses found in Taiwanese children (e.g.

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Copper electrocatalysts have been shown to selectively reduce carbon dioxide to hydrocarbons. Nevertheless, the absence of a systematic study based on time-resolved spectroscopy renders the functional agent-either metallic or oxidative Copper-for the selectivity still undecidable. Herein, we develop an operando seconds-resolved X-ray absorption spectroscopy to uncover the chemical state evolution of working catalysts.

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Organic fluorescent molecules play critical roles in fluorescence inspection, biological probes, and labeling indicators. More than ten thousand organic fluorescent molecules were imported in this study, followed by a machine learning based approach for extracting the intrinsic structural characteristics that were found to correlate with the fluorescence emission. A systematic informatics procedure was introduced, starting from descriptor cleaning, descriptor space reduction, and statistical-meaningful regression to build a broad and valid model for estimating the fluorescence emission wavelength.

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First-principles investigations on 1D TiS(en) are performed to evaluate its potential as an electrode for lithium ion batteries. The intercalation of lithium ions into LiTiS(en) follows the Rüdorff model and the lithium ions are predicted to diffuse along the one-dimensional axis of the TiS(en) nanostructure with a small diffusion barrier of 0.27 eV.

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Nowadays identifying a high-performance catalyst for converting methane to methanol is crucial because methanol serves as an excellent energy source and has wide chemical applications. In the present study, we used DFT, a computational chemistry method, to investigate the reaction mechanism of methanol production by conversion of methane on Pt nanoparticles supported on graphene oxide (GO) substrates. Computational results predicted that the Pt/GO system exhibits excellent catalysis efficiency, compared with those of the previously examined Pt/GO and PtO/GO systems.

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The generation of ammonia, hydrogen production, and nitrogen purification are considered as energy intensive processes accompanied with large amounts of CO emission. An electrochemical method assisted by photoenergy is widely utilized for the chemical energy conversion. In this work, earth-abundant iron pyrite (FeS ) nanocrystals grown on carbon fiber paper (FeS /CFP) are found to be an electrochemical and photoactive catalyst for nitrogen reduction reaction under ambient temperature and pressure.

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Composite electrocatalysts have exhibited high activities toward water electrolysis, but the catalytically active sites really in charge of the reaction are still debatable while the conventional in situ X-ray spectroscopies are not capable of conclusively identifying the interaction of these materials with the electrolyte because of the complexity of catalysis. In this work, by utilization of operando K high-energy resolution fluorescence-detected X-ray absorption spectroscopy (HERFD-XAS) with a small incident angle, the operando quadrupole transition obviously showed that oxygen directly interacted with 3d orbitals of Co ions rather than that of Fe ions. Most importantly, Fe ions can promote the stabilization of the Co ions under a higher valent state during water oxidation, which may lead to a stable intermediate of reactant and its superior intrinsic activity.

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The catalytic role of Cu ions in CO2 reduction on oxide-derived Cu has been elusive. In the presence of oxygen vacancy, COCO dimerization is predicted to be thermodynamically favorable with an accessible barrier on Cu4O3(202). The material's mixed valency is responsible for stabilizing the charge-separated (OC)δ+(CO)δ- intermediate.

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II-VI semiconductors exhibit unique behaviors that can generate dual-holes ("heavy and light"), but the application in photocatalysis is still missing. Herein, an empirical utilization of light/heavy holes in a hybrid metal cluster-2D semiconductor nanoplatelets is reported. This hybrid material can boost the hole-transfer at the surface and suppress the recombination.

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The catalytic activity for the adsorption and dehydrogenation of alkanes (CH, n = 2, 3, 4) on a low-symmetry Rh cluster (Rh-L) is compared with a system consisting of the same cluster (Rh-L) supported on either an unzipped graphene-oxide (UGO) sheet (Rh-L/UGO) or a TiO(110) surface (Rh-L/TiO). The adsorption energies of these alkanes, calculated using density-functional theory, follow the order Rh-L/TiO ≈ Rh-L/UGO > Rh-L. Our proposed reaction path for the dehydrogenation of ethane, propane and butane on Rh-L/UGO has first barrier heights of 0.

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The catalytic activity of rhodium nanoclusters (Rh13) on unzipped graphene oxide (Rh13/UGO) has been investigated for comparison with Rh13 nanoclusters and Rh(111) surfaces. The binding energy of Rh atoms on UGO is less than the cohesive energy (-5.75 eV) of bulk Rh, indicating that the Rh atoms adsorbed on UGO tend to collect into clusters.

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Enabled by the reversible conversion between Li2O2 and O2, Li-O2 batteries promise theoretical gravimetric capacities significantly greater than Li-ion batteries. The poor cycling performance, however, has greatly hindered the development of this technology. At the heart of the problem is the reactivity exhibited by the carbon cathode support under cell operation conditions.

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Evaporation-induced convective binary assembly of large (A) and small (B) silica nanoparticles is demonstrated as a template-free route to three-dimensionally ordered mesoporous silicas (OMSs), the pore topology of which derives from the interconnected interstices of the resulting ordered nanoparticulate structures. Even without explicit solvent index matching or stabilization (e.g.

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We applied density-functional theory (DFT) to investigate the adsorption and dissociation of NO on Rh19 and Ni19 clusters with a double-icosahedral (DI) structure. The transition structures of the NO dissociating on the potential-energy surfaces were derived using the nudged-elastic-band (NEB) method. The adsorption energies of NO molecules on the rhombus-center region of DI clusters are -2.

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Fundamental understanding of the mass transport of petrochemical and biomass derived molecules in microporous and mesoporous solid catalysts is important for developing the next generation of heterogeneous catalysts for traditional hydrocarbon processing including biomass pyrolysis and upgrading. Hierarchical zeolites with both micropores and mesopores exhibit enhanced mass transport and unique catalytic performance in reactions involving large molecules. However, quantitative description of mass transport in such materials remains elusive, owing to the complicated structure of hierarchical pores and difficulty in the synthesis of the materials with controllable structures.

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Due to the rather low efficiencies of conjugated polymers in solid films, their successful applications are scarce. However, recently several experiments indicated that a proper control of molecular conformations and stresses acting on the polymers may provide constructive ways to boost efficiency. Here, we report an amazingly large enhancement of photoluminescence as a consequence of strong shear forces acting on the polymer chains during nanofilm dewetting.

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We applied density-functional theory (DFT) with the projector-augmented-wave method (PAW) to investigate systematically the energetics of C-N coupling reactions on Pt(111) and Ni(111)surfaces. Our approach includes several steps: the adsorption of reactants and products (CHx, NHy and CHxNHy, x = 0-3, y = 0-2), movement of molecular fragments on the surface, and then C-N coupling. According to our calculations, the energies (ignoring the conventional negative sign) of adsorption of CHx and NHy on Pt(111)/Ni(111) surfaces decrease in the order C > CH > CH2 > CH3 and N > NH > NH2, with values 7.

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