Construction of a Nanoporous Highly Crystalline Hexagonal Boron Nitride from an Amorphous Precursor for Catalytic Dehydrogenation

Abstract

Hexagonal boron nitride (h-BN) is regarded as agraphene analogue and exhibits important characteristics and vast application potentials.H owever,d iscoveringafacile method for the preparation of nanoporous crystalline h-BN nanosheets (h-BNNS) is still ac hallenge.H erein, an ovel and simple route for the conversion of amorphous h-BN precursors into highly crystalline h-BNNS was achieved through asuccessive dissolution-precipitation/crystallization process in the presence of magnesium. The h-BNNS has high crystallinity, high porosity with asurface area of 347 m 2 g À1 ,high purity,and enhanced thermal stability.Improved catalytic performance of crystalline h-BNNS was evidenced by its muchhigher catalytic efficiency in the dehydrogenation of dodecahydro-N-ethylcarbazole,c ompared with its amorphous h-BN precursor,a s well as other precious-metal-loaded heterogeneous catalysts.

Computationally aided, entropy-driven synthesis of highly efficient and durable multi-elemental alloy catalysts

“…To address these needs, multi-elemental alloy nanoparticles (MEA-NPs) demonstrate great potential for catalyst discovery and property optimization, with an expansive and underexplored compositional space (6,7). In addition, the uniform mixing of multiple elements increases the system entropy and provides an entropy-driven, thermodynamically (G = H − T*S) and kinetically (sluggish diffusion) stabilized structure that can sustain harsh service environments (high temperature, corrosion, and high electrochemical potential) (8)(9)(10), which have been also verified in other high-entropy materials (11)(12)(13)(14). Preliminary experimental results have shown the enhanced catalytic performance of MEA-NPs compared with existing unary or binary systems (6,7,15,16).…”

Advances in MXene Films: Synthesis, Assembly, and Applications

“…Since the discovery of mechanically exfoliated graphene in 2004 [1], research on ultrathin two-dimensional (2D) nanomaterials has grown exponentially in the fields of materials, material chemistry, and nanotechnology. Following graphene, a variety of 2D nanomaterials, such as antimonene [2,3], phosphorene [4], hexagonal boron nitride [5], transition metal disulfides [6], layered metal oxides, and layered double hydroxides, have been reported [7,8]. These ultrathin 2D materials have unique physical and chemical properties that are different from bulk materials because of the existence of quantum confinement effects [9].…”

Ambient Temperature Graphitization Based on Mechanochemical Synthesis

“…Mg was verified to be capable of lowering the graphitization temperature of hard carbons (<1000 °C) as an efficient metal catalyst [18] and promoting the denitriding reaction of N‐rich materials at 750 °C [29] . Our group has also demonstrated the construction of highly crystalline hexagonal boron nitride nanosheets from an amorphous counterpart in the presence of Mg at 900 °C [30] . Considering the low cost and good performance of Mg in the above‐mentioned procedures, herein Mg will be adopted as the corresponding metal catalyst for high‐quality graphite preparation.…”