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By means of quantum Monte Carlo (QMC) calculations from first-principles, we study the ground-state properties of the narrowest zigzag graphene nanoribbon with an infinite linear acene structure. We show that this quasi-one-dimensional system is correlated and its ground state is made of localized π electrons whose spins are antiferromagnetically ordered. The antiferromagnetic (AFM) stabilization energy [36(3) meV per carbon atom] and the absolute magnetization [1.13(0.11) μB per unit cell] predicted by QMC are sizable, and they suggest the survival of antiferromagnetic correlations above room temperature. These values can be reproduced to some extent by density functional theory (DFT) within the DFT+U framework or by using hybrid functionals. Based on our QMC results, we then provide the strength of Hubbard repulsion in DFT+U suitable for this class of systems. [ABSTRACT FROM AUTHOR]

This work examined the location-steered catalytic behavior of Mo/ZSM-5 catalyst for one-step methane dehydroaromatization to benzene reaction. The results indicated that α-site is the preferred location for the formation of ethylene, the main intermediate for aromatics production via the propagation pathway, while δ-site is favorable for the hydrocarbon pool aggregation reaction pathway. [ABSTRACT FROM AUTHOR]

Photogenerated charge separation and transfer is one of the bottleneck steps in photocatalysis, and efficient charge separation strategies are strongly desired. Here, mimicking the electron transport chain in natural photosynthesis, we report the design and fabrication of a charge transfer chain using bismuth-based semiconductor as a proof-of-concept. In view of the thermodynamic energy band positions and structural similarity based on the density functional theory (DFT) analysis, heterostructured combination of α-Bi2O3, perovskite-like Bi4Ti3O12, and sillenite Bi12TiO20 was designed for fabrication of charge transfer chain. By tuning the molar ratio of Bi and Ti precursors, the Bi4Ti3O12 and Bi12TiO20 particles were formed on the surface of α-Bi2O3 by an in-situ transformation process, giving rise to Bi12TiO20-Bi4Ti3O12/α-Bi2O3 composites with charge transfer chain. We propose that the effective charge transfer is accomplished among α-Bi2O3, Bi12TiO20, and Bi4Ti3O12, which significantly improves the photogenerated charge separation and transfer, as indicated by photoluminescene, time-resolved photoluminescene, and electrochemical impedance spectra results. As expected, the Bi12TiO20-Bi4Ti3O12/α-Bi2O3 shows the superior photocatalytic activity for the degradation of environmental pollutants with high concentration. Even for the refractory pollutants like 4-chlorophenol, the optimal Bi12TiO20-Bi4Ti3O12/α-Bi2O3 composite shows 28 times higher than that of α-Bi2O3 for photocatalytic degradation, verifying the superiority of photogenerated charge transfer chain in photocatalysis. This work demonstrates the feasibility of the charge transfer chain strategy to boost the photogenerated charge separation, which is of great significance for designing energy and environmental-related materials in heterogonous photocatalysis. [ABSTRACT FROM AUTHOR]

Photoreduction of CO2 into solar fuels has received great interest, but suffers from low catalytic efficiency and poor selectivity. Herein, two single‐Cu‐atom catalysts with unique Cu configurations in phosphorus‐doped carbon nitride (PCN), namely, Cu1N3@PCN and Cu1P3@PCN were fabricated via selective phosphidation, and tested in visible light‐driven CO2 reduction by H2O without sacrificial agents. Cu1N3@PCN was exclusively active for CO production with a rate of 49.8 μmolCO gcat−1 h−1, outperforming most polymeric carbon nitride (C3N4) based catalysts, while Cu1P3@PCN preferably yielded H2. Experimental and theoretical analysis suggested that doping P in C3N4 by replacing a corner C atom upshifted the d‐band center of Cu in Cu1N3@PCN close to the Fermi level, which boosted the adsorption and activation of CO2 on Cu1N3, making Cu1N3@PCN efficiently convert CO2 to CO. In contrast, Cu1P3@PCN with a much lower Cu 3d electron energy exhibited negligible CO2 adsorption, thereby preferring H2 formation via photocatalytic H2O splitting. [ABSTRACT FROM AUTHOR]

Supported metal catalysts have shown to be efficient for CO2 conversion due to their multifunctionality and high stability. Herein, we have combined density functional theory calculations with microkinetic modeling to investigate the catalytic reaction mechanisms of CO2 hydrogenation to CH3OH over a recently reported catalyst of Cd4/TiO2. Calculations reveal that the metal‐oxide interface is the active center for CO2 hydrogenation and methanol formation via the formate pathway dominates over the reverse water‐gas shift (RWGS) pathway. Microkinetic modeling demonstrated that formate species on the surface of Cd4/TiO2 is the relevant intermediate for the production of CH3OH, and CH2O# formation is the rate‐determining step. These findings demonstrate the crucial role of the Cd‐TiO2 interface for controlling the CO2 reduction reactivity and CH3OH selectivity. [ABSTRACT FROM AUTHOR]