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Although zeolite nanosheets (NSs) exhibit great prospects for a wide range of applications due to microstructural superiority, their facile preparation and microstructural tailoring remain a great challenge. In this study, uniform coffin-shaped MFI microcrystals were subjected to hydrothermal treatment in the presence of different types of alkaline etching agents, i.e., TMAOH, TEAOH, and TPAOH, for preparing MFI NSs with distinctive microstructures. It was found that the morphological and textural properties of MFI NSs could be readily tuned by varying etching agent types, etching agent contents, and hydrothermal treatment parameters, thereby leading to the formation of 10 nm thick leaf-shaped MFI NSs, ellipse-shaped MFI NSs, and single-crystal-like MFI NS aggregates through an in-plane oriented attachment. Simultaneously, the possible mechanisms involved in the formation of MFI NSs with distinctive microstructures were proposed. Among the prepared MFI NSs, 10 nm thick (ca. 5 unit cell) leaf-shaped MFI NSs represented one of the thinnest MFI NSs ever reported by the top-down method, while single-crystal-like MFI NS aggregates were prepared for the first time, which may endow them with superior performances in relevant application areas.

Limited by the chemical inertness of CO2and the high dissociation energy of the C═O bond, photocatalytic CO2conversion is highly challenging. Herein, we prepare ultrathin oxygen-modified h-BN (O/BN) nanosheets containing B–O bonds. On the O/BN surface, CO2can be chemically captured and is bonded with the B–O bond, leading to the formation of an O–B–O bond. This new chemical bond acting as an electron-delivery channel strengthens the interaction between CO2and the surface. Thus, the reactants can continuously obtain electrons from the surface through this channel. Therefore, the majority of gaseous CO2directly converts into carbon active species that are detected by in situ DRIFTS over O/BN. Moreover, the activated energies of CO2conversion are significantly reduced with the introduction of the B–O bond evidenced by DFT calculations. As a result, O/BN nanosheets present an enhanced photocatalytic CO2conversion performance with the H2and CO generation rates of 3.3 and 12.5 μmol g–1h–1, respectively. This work could help in realizing the effects of nonmetal chemical bonds in the CO2photoreduction reaction for designing efficient photocatalysts.

In this study, we reported a novel synthesis strategy to prepare monodispersed single-crystalline hierarchical ZSM-5 nanosheets featuring high crystallinity, tunable Si/Al ratios, and excellent stability via anisotropic etching in aqueous TPAOH solution, which exhibited superior catalytic performance in methanol aromatization reaction.