Jingyu Pang

A large number of low coordinated atoms in boron nitride for outstanding adsorptive desulfurization performance

h-BN has been demonstrated to be able to exhibit adsorptive desulfurization from fuel. In order to further optimize the adsorption capacities to meet the potential industrial applications, tuning the nanostructure of BN was taken into account. In this work, we demonstrated that cyanamide, dicyandiamide, and melamine as different nitrogen precursors for synthesizing BN could tune the BN nanoarchitectures. The high performance BN prepared with melamine presented a ribbon-like structure which was assembled with porous nanosheets. This kind of nanoarchitecture with exposed BN sharp edges and a porous structure can be constructed on the BN surface. The large number of low coordinated atoms at the exposed sharp edges and along the edges of the pores could build powerful interaction with sulfide, which was believed to be responsible for the advanced adsorption capacity. The prepared BN with melamine as nitrogen precursors displayed remarkable adsorption performance for DBT (40.2 mg S per g adsorbent for 500 ppm sulfur model oil and 57.5 mg S per g adsorbent according to the Langmuir isotherm model). To the best of our knowledge, it is the highest adsorption capacities reported so far for the adsorptive desulfurization. It is also noteworthy to mention that even for refractory sulfur compound 4,6-DMDBT, the prepared BN still showed high adsorption performance.

Tuning electronic properties of boron nitride nanoplate via doping carbon for enhanced adsorptive performance.

In this paper, the carbon-doped boron nitride nanoplate (C-BNNP) was prepared by pyrolyzing the precursor under N2 and served as an excellent adsorbent for removal of Rhodamine B (RhB). The structure and composition of C-BNNP were characterized and its adsorption behavior for RhB was investigated. Compared with boron nitride nanoplate (BNNP) which was synthesized under NH3, C-BNNP displayed an enhancement of the adsorption capacity for RhB (833mg/g). The adsorption activity was comprehensibly studied by kinetics, isotherm and thermodynamics. The adsorption kinetics followed pseudo-second-order model. The equilibrium adsorption data agreed well with the Langmuir isotherm. And the thermodynamics indicated that the adsorption process was a spontaneous, exothermic and physisorption process. In addition, the density functional theory was proposed that doping carbon in the BNNP decreased the chemical hardness of the adsorbent and enhanced the adsorption capacity of C-BNNP for RhB.

Green aqueous biphasic systems containing deep eutectic solvents and sodium salts for the extraction of protein

Deep eutectic solvents (DESs), a new type of green solvents, were applied for the extraction of proteins with aqueous biphasic systems (ABSs) in this study. The structures of the prepared DES were confirmed by FT-IR and 1H NMR. The DES–salt (NaH2PO4/Na2CO3/Na3C6H5O7)-based ABSs were established and applied to extract the bovine serum albumin and papain. DES–Na2CO3 ABS was selected as the suitable extraction system. Single-factor experiments were investigated to achieve complete extraction by properly tailoring the concentration of different compositions (e.g. proteins, Na2CO3, DES), the temperature and pH values. The experimental results indicated that the extraction efficiency could reach up to 95.16% for bovine serum albumin and 90.95% for papain under the optimum conditions. UV-vis spectra, fluorescence spectra and CD spectra were investigated to confirm that the conformation of bovine serum albumin did not change after extraction. The transmission electron microscopy (TEM) was used to explore the mechanism of the extraction. All of these results indicated that DES-based ABSs may provide a new possibility for the separation of proteins.

Tuning the Chemical Hardness of Boron Nitride Nanosheets by Doping Carbon for Enhanced Adsorption Capacity

The chemical hardness of adsorbents is an important physicochemical property in the process of adsorption based on the hard and soft acids and bases (HSAB) theory. Tuning chemical hardness of adsorbents modulated by their concomitants is a promising approach to enhance the adsorptive capacity in principle. In the present work, we report an efficient strategy that the adsorption capacity for aromatic sulfocompounds can be enhanced by tuning the chemical hardness. This strategy is first theoretically explored by introducing C element into the network of hexagonal boron nitride (h-BN) based on a series of model materials (model_xC, x = 1–5). Computational results show that the chemical hardness is reduced after gradually C-doping, which may lead to an enhancement of adsorption capacity according to the HSAB theory. Then, a series of C-doped h-BN materials (BCN-x, x = 10–50) were controlled synthesized. All of the as-prepared materials show better adsorption capacities (e.g., 27.43 mg g–1 for BCN-50) than pure h-BN. Experiment results show that the adsorption capacity correlates well with the C content in the BCN-x, which is consistent with the results predicted by theoretical calculation. This strategy may be helpful to rationally design highly efficient adsorbents in separation engineering and may be expanded to similar two-dimensional materials, where the π–π interaction is the dominant driven force.