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Photocatalytic nitrogen fixation is of great significance for solving the energy crisis and healthy development of the environment. However, photocatalysts have problems such as low activity, poor stability and difficult recovery, which seriously limit their application. Herein, we in situ synthesized g-C 3 N 4 /Ni 2 P/Ni three-dimensional reticulated foam photocatalysts (CNNPF) with excellent photocatalytic nitrogen fixation performance under visible light by a two-step methane sulfonic acid-assisted carbon nitride loading-calcined phosphatisation method, using nickel foam as the carrier and raw material. The results showed that the CNNPF had a stable three-dimensional network structure, and g-C 3 N 4 was stably immobilized to the nickel foam skeleton with Ni 2 P. The best performance of CNNPF with ultrasonication for 2 h and phosphatisation for 1 h showed a high photocatalytic nitrogen fixation efficiency of up to 373 μmol·h−1·g−1, which was attributed to the Ni 2 P co-catalyst modification of g-C 3 N 4 that led to the improvement of photogenerated electron-hole pair separation efficiency. Meanwhile, the three-dimensional network structure is favorable to provide more active sites for N 2 adsorption and activation. In addition, the prepared material also has good stability and recyclability, and its nitrogen fixation efficiency was still maintained at 350 μmol·h−1·g−1 after five cycles. The present work provides a direction for the design of efficient and recyclable photocatalytic systems that show great potential in the field of economically sustainable nitrogen fixation. [Display omitted] • g-C 3 N 4 /Ni 2 P/Ni three-dimensional reticulated foam photocatalysts (CNNPF) were in situ synthesized. • CNNPF has excellent photocatalytic nitrogen fixation performance under visible light. • Ni 2 P modification of g-C 3 N 4 to improve photogenerated electron-hole pair separation efficiency. • CNNPF also has good stability and recyclability. [ABSTRACT FROM AUTHOR]

Chitosan (CS) is an excellent raw material for the preparation of food packaging films due to its good film-forming properties, non-toxicity, and biodegradability. However, pure chitosan films have drawbacks such as weak mechanical properties and limited antimicrobial activity. In this work, novel food packaging films containing chitosan, polyvinyl alcohol (PVA) and porous graphitic carbon nitride (g-C 3 N 4) were successfully prepared. The PVA served to improve the mechanical properties of the chitosan-based films, whilst the porous g-C 3 N 4 acted as a photocatalytically-active antibacterial agent. The tensile strength (TS) and elongation at break (EAB) of the g-C 3 N 4 /CS/PVA films both increased by ~4 times compared to the pristine CS/PVA films at the optimum g-C 3 N 4 loading of ~10 wt%. The addition of g-C 3 N 4 increase the water contact angle (WCA) of the films from 38° to 50°, whilst decreasing the water vapor permeability (WVP) from 160 × 10−12 to 135 × 10−12 g∙Pa−1 s−1 m−1. The shelf life of strawberries covered with g-C 3 N 4 /CS/PVA films at room temperature could be extended up to 96 h, compared to 48 h and 72 h for strawberries covered with polyethylene (PE) films or CS/PVA films, respectively. The g-C 3 N 4 /CS/PVA films offered good antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Further, the composite films could be easily recycled with the regenerated films offering almost identical mechanical properties and activities as the original films. The prepared g-C 3 N 4 /CS/PVA films thus offer promise for low-cost antimicrobial packaging applications. [Display omitted] • g-C 3 N 4 /CS/PVA photocatalytic packaging film was successfully prepared. • g-C 3 N 4 enhanced the barrier ability and antibacterial activity of the film. • PVA enhanced the mechanical properties and flexibility of the film. • The composite film showed better strawberries packaging properties. • The composite film can be easily recycled to prepare renewable film. [ABSTRACT FROM AUTHOR]

Nanosized photocatalysts have the obvious disadvantages in recovering and recycling process during the wastewater treatment. To overcome the above shortcomings, graphitic carbon nitride/polyvinyl alcohol (g-C 3 N 4 /PVA) photocatalytic composite sponge was prepared simply by introducing graphitic carbon nitride (g-C 3 N 4) photocatalyst into polyvinyl alcohol (PVA) sponge via copolymerization method during the cross-linking process. The characterization results indicated that the g-C 3 N 4 /PVA composite sponge has the porous structure and g-C 3 N 4 nanoparticles have been attached uniformly and tightly throughout the porous structure of the PVA sponge. Furthermore, the composite sponge has excellent elastic deformation property and can be easily tailored into designed shapes without destroying the structure of the sponge. Thirdly, the composite sponge shows efficient adsorption and photodegradation properties for removing of organic pollutants rhodamine B (RhB) and tetracycline (TC) from wastewater. It is worth to note that the prepared g-C 3 N 4 /PVA composite sponge can be easily recovered from the wastewater solution and shows stable recycling property. Our method to combine g-C 3 N 4 photocatalysts into PVA sponge provides a facile technique to construct stable photocatalysts with recyclable and photocatalytic degradation properties in the field of wastewater treatment. [Display omitted] • Stable g-C 3 N 4 /PVA photocatalytic composite sponge were simply prepared. • g-C 3 N 4 nanoparticles attached uniformly and tightly throughout the sponge. • The composite sponge shows elastic and easily tailoring properties. • The composite sponge shows efficient photocatalytic removal of RhB and TC. • The composite sponge has stable recycling property. [ABSTRACT FROM AUTHOR]

[Display omitted] • The sodium dehydroacetate-loaded diatomite (SD/D) was fabricated. • The SD/D composite films have excellent water and atmospheric conditioning performance. • The potential applications as preservation film have been demonstrated. • The SD/D composite films showed excellent long-acting antimicrobial ability. Biodegradable food packaging films with good antimicrobial properties are highly sought after for prolonging the shelf-life of fruits and vegetables whilst minimizing waste streams originating from the food sector. In this work, a series of PBAT/PLA food packaging films containing sodium dehydroacetate-loaded diatomite (SD/D) as an antimicrobial agent were fabricated. Structural analyses showed that the sodium dehydroacetate was incorporated into the pores of the diatomite. A uniform dispersion of SD/D in the composite films effectively enhanced water and gas permeability, whilst also giving the films good mechanical properties. The slow release of SD endowed the composite films with long-acting antibacterial ability (>90 % bacteriostasis rate for E. coli and >85 % bacteriostasis rate for S. aureus). The composite films were able to effectively maintain the quality of banana fruits during storage at room temperature, encouraging their use in food applications where non-biodegradable petrochemical-derived packaging films have traditionally been used. [ABSTRACT FROM AUTHOR]