In this paper, a novel three dimensional carbon boron nitride (3D C-BN) was successfully prepared. The obtained material has porous cheese-like structure and pore size ranging from 2 nm to 100 nm. Attractively, the 3D C-BN, which combines the adsorption advantages of BN and carbon together, exhibits excellent adsorption properties for organic dyes, oils and heavy metal ions. The maximum removal capacities of 3D C-BN for methyl blue (MB) and congo red (CR) are 408 mg g−1 and 307 mg g−1, respectively. Furthermore, 3D C-BN can quickly and efficiently remove oils (salad oil, gasoline and pump oil) and heavy metal ions (Cr3+, Cd2+ and Ni2+) from waste water. The macro bulk 3D C-BN, which is more convenient to use than powdered materials, can be reused by burning or heating in air and still maintains high adsorption capacity. Significantly, these superior performances can find practical application in water purification.

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Developing membranes with excellent mechanical strength and chemical stability is a practically important issue for efficient removal of pollutants from wastewater. In this work, we report on a free-standing membrane fabrication from an activated boron nitride (ABN) micro-ribbon. The membrane techniques we used, combine the intrinsic active adsorption competence of ABN and the mechanical advantages of conventional membrane filtration. The obtained membranes show an excellent removal ability of water pollutants through a simple filtration adsorption process. The examined pollutants include toxic metallic ions and organics. We showed that the dye (like methylene blue) removal ability significantly exceeded that of activated carbon by an order of magnitude at least; lead ions (Pb 2+ ) in wastewater can be nearly fully removed, the starting 5 mg L À1 concentration was reduced to less than 0.01 mg L À1 after the 600 mm-thickness membrane adsorption filtration. Moreover, the membranes can be stacked together to further improve the adsorption capacity because of their high permeability. The excellent reusable performance of the filtration membranes was also confirmed. We believe that the reported work should open the way toward the practical application of ABN membranes in the field of wastewater purification.

Adsorption–photocatalytic synergistic removal of organic pollutants based on porous BN coupled with a small amount of CdS.

Volatile organic compounds, especially formaldehyde (HCHO), are considered to be great sources of contaminants in indoor air. However, design and preparation of safe, cost-affordable, and reusable materials for HCHO removal at ambient conditions are still remarkably challenging. Here, we have developed a kind of novel NaOH-embedded three-dimensional porous boron nitride (NaOH-3D BN) with high and hierarchical porosities, which exhibit excellent removal performance for HCHO. The as-prepared 3D BN is used as an adsorbent and catalytic support, while the embedded NaOH is applied as a catalyst, giving rise to catalytic transformation from high-toxic HCHO to less-toxic formate and methoxy salts at room temperature. Furthermore, their effective reusability has been confirmed. Given the high removal and reusability performance as well as no use of precious materials, the NaOH-3D BN is envisaged to be valuable practically for indoor air purification.

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Direct use of zero-valent iron (ZVI) in reductive removal of selenate (Se(VI)) is inefficient due to the intrinsic passive layer of ZVI. Here we observed that ZVI pretreated with H2O2 (P-ZVI-O) performs much better in Se(VI) removal from a mining effluent than other three modes of ZVI alone, acid washing ZVI (P-ZVI-A), and simultaneous addition of H2O2 and ZVI (ZVI-O) as well. The P-ZVI-O exhibits exceptionally high Se(VI) removal at a low dosage, wide pH range, with Se dropping down from 93.5 mg/L to <0.4 μg/L after 7-h reaction. Interestingly, the initial pH (2–6) of the mining effluent exerted little influence on the final Se(VI) removal. H2O2/HCl pretreatment results in the formation of various reducing corrosion products (e.g. Fe3O4, FeO and Fe2+), which greatly favors the efficient Se(VI) removal. In addition, surface-bound Fe2+ ions participated in the reduction of Se(VI). Combined with the influence of Se valence as well as pH and Fe2+ (whether dissolved or surface bound), it is deduced that the P-ZVI-O mode induced efficient Se(VI) removal via the adsorption-reduction and/or co-precipitation. This study demonstrates that H2O2/HCl pretreatment of ZVI is a very promising option to enhance the efficiency of reductive removal of Se(VI) from real effluents.