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In this work, 2,6-diaminoanthraquinone (DAAQ)-1,3,5-triformylphloroglucinol (TFP) COF/CuS heterojunction was supported on cellulose fibers with hyperbranched polyamide-amine (HPAMAM) as growth template and stabilizer to prepare composite paper for photocatalytic degradation of organic dyes in water. HPAMAM was grafted onto dialdehyde cellulose fibers (DACF) via Schiff base reaction. The intramolecular cavities of HPAMAM provided suitable sites for the growth of COF/CuS heterojunction, and the flexible polymer chains of HPAMAM were used to disperse and stabilize the COF/CuS heterojunction. COF provided an ideal framework for the adsorption, diffusion, and activation of organic dyes in water. And the photogenerated electron transfer path in the COF/CuS heterojunction formed a Z scheme model, which enhanced the separation efficiency of photogenerated electrons and maximized the redox potential for high photocatalytic activity. The DACF/HPAMAM/COF/CuS paper exhibited the highest photocatalytic reaction rate (k = 0.5549 min−1), 7.4 times higher than that of DACF/HPAMAM/COF paper and 6.2 times higher than that of DACF/HPAMAM/CuS paper. To the best of our knowledge, this is one of the best performances for photocatalytic degradation of organic dyes. The DACF/HPAMAM/COF/CuS paper also showed good photocatalytic cycling stability and structural stability. This study provides a strategy for constructing COF/inorganic semiconductor Z scheme heterojunction on cellulose fibers to prepare photocatalytic paper and demonstrates a breakthrough in the field of photocatalytic degradation of organic dyes in water. [ABSTRACT FROM AUTHOR]

[Display omitted] The highly dispersed small-size metal co-catalysts can effectively improve the photocatalytic efficiency of semiconductor photocatalysts by separating photogenerated electrons and enriching active sites. However, this system tends to aggregate in the absence of carrier, resulting in the decrease of active sites. Here, MOF-derived carbon skeleton (MDCS) encapsulated Ni nanoparticles (Ni@MDCS) and BiOBr was loaded onto carbonized cellulose fibers (CCF) with the help of polydopamine (PDA) to construct high-performance and recyclable photocatalytic paper for photocatalytic degradation of organic dyes in water. The characterization results showed that MDCS promoted good dispersion of Ni nanoparticles and provided sufficient active sites. And Ni@MDCS as a co-catalyst accelerated the separation of photogenerated carriers in BiOBr. The PDA improved the loading state of Ni@MDCS on CCF and converted into N -doped C in the carbonization process for further increasing the transfer efficiency of photogenerated electrons. In the composite paper, the stable loading of Ni@MDCS/BiOBr hybrid on CCF improved the dispersion and reusability of photocatalyst. The degradation rate of rhodamine B on CCF/PDA-C/Ni@MDCS/BiOBr paper was as high as 94.6 % after 60 min visible light irradiation, which was about 2.5 times higher than that of CCF/BiOBr paper. During 10 cycles, CCF/PDA-C/Ni@MDCS/BiOBr paper maintained high photocatalytic efficiency and good structural stability. This study provides a new way for developing high-performance and recyclable photocatalytic paper. [ABSTRACT FROM AUTHOR]

[Display omitted] The O-vacancy Bi 2 WO 6 /SrTiO 3 heterojunction photocatalyst with Z scheme photogenerated electron transfer mechanism was loaded on cellulose fibers to construct a visible light-responsive photocatalytic composite paper for efficient and recyclable degradation of organic dyes in water. The introduction of O vacancies in Bi 2 WO 6 by alkali etching increased the utilization rate of Bi 2 WO 6 for visible light and achieved effective regulation of the energy band structure and Fermi level, which transformed Bi 2 WO 6 /SrTiO 3 type-II heterojunction into Z scheme heterojunction. The light-excited electrons in the conduction band of O-vacancy Bi 2 WO 6 directly migrated to the valence band of SrTiO 3 , which improved the separation efficiency of photogenerated carriers and maximized the redox capability of semiconductors. Compared with other control papers, O-vacancy Bi 2 WO 6 /SrTiO 3 paper exhibited the best photocatalytic performance, and its degradation rate for rhodamine B could reach 71.1% under 100 min of Xe lamp irradiation. The O-vacancy Bi 2 WO 6 /SrTiO 3 paper also showed good photocatalytic cycle stability. Loading heterojunction on the cellulose fibers solved the problem of poor reusability and difficult in recovery for powder semiconductor photocatalyst in practical applications. This study provides a novel strategy for constructing Z scheme heterogeneity on cellulose fibers to prepare composite paper with high photocatalytic activity and good reusability. [ABSTRACT FROM AUTHOR]

Due to its narrow band gap, Copper sulfide (CuS) exhibits great potential in photocatalytic degradation of organic dyes. However, there are still some drawbacks in the CuS photocatalytic system, such as easy aggregation, poor reusability, high recombination rate of photogenerated electron-hole pair, and photocorrosion damage. In this study, CuS was anchored onto cellulose fibers (CF) with the help of polydopamine (PDA) for constructing composite paper (CF/PDA/CuS paper) with high photocatalytic efficiency and good reusability. After PDA coatings formed on cellulose fibers, the chelation of Cu2+ by the catechol group of PDA provided uniform and stable growth sites for CuS, resulting in CuS anchoring in the PDA matrix for increasing the loading capacity and stability of CuS on cellulose fibers. In addition, PDA improved the separation efficiency of photogenerated electrons in CuS and inhibited the photocorrosion of CuS. The CF/PDA/CuS paper exhibited prominently enhanced photocatalytic activity and photocatalytic stability for the degradation of Rhodamine B under near infrared light irradiation. The photocatalytic activity of CF/PDA/CuS paper was about 5.8 times higher than that of CF/CuS paper. During 10 cycles, the photocatalytic efficiency of CF/PDA/CuS paper for degrading Rhodamine B was always above 92 % and the PDA/CuS hybrid structure was always stable on cellulose fibers. This work inspires the construction of stable PDA/CuS hybrid structure on cellulose fibers for a composite paper with high photocatalytic efficiency and good reusability. • A novel CuS-based photocatalytic composite paper was prepared. • The PDA coatings formed on the cellulose fibers were used to anchor CuS. • The chelation of Cu2+ by the catechol group of PDA provided growth sites for CuS. • PDA separated the photogenerated electrons and inhibited the photocorrosion of CuS. • The composite paper exhibited high photocatalytic activity and good reusability. [ABSTRACT FROM AUTHOR]

• A novel CuS-based photocatalytic composite paper is prepared. • The load of reduced graphene oxide on fibers relies on hyperbranched polyamide-amine. • Hyperbranched polyamide-amine grafted on fibers induces uniform growth of CuS. • Reduced graphene oxide inhibits the recombination of photogenerated carriers in CuS. • The composite paper exhibited high photocatalytic activity and good reusability. The use of semiconductor-based photocatalysts to degrade organic dyes in water is receiving more and more attention. However, there are still some problems in practical applications, such as high photogenerated carrier recombination rate, difficulty in recovery, and poor reusability. In this study, reduced graphene oxide (rGO)/copper sulfide (CuS) was loaded onto a dialdehyde cellulose fiber (DACF) with the help of hyperbranched polyamide-amine (HPAMAM) to construct a photocatalytic composite paper (DACF/HPAMAM/rGO/CuS paper). Based on the results, HPAMAM was bonded to DACF and rGO via C N and amide bond, and it could act as a nanoreactor to induce uniform and stable growth of CuS. The photocatalytic activity of the as-prepared DACF/HPAMAM/rGO/CuS paper in the degradation of rhodamine B was about 2.7 times that of the composite paper without HPAMAM and rGO (DACF/CuS paper). Such a high performance could be attributed to the improved charge separation efficiency and the stable composite structure of rGO/CuS in the composite paper. DACF/HPAMAM/rGO/CuS paper was also able to demonstrate excellent stability and reusability, which makes it a promising photocatalyst. This work provides a novel strategy for preparing highly efficient and stable photocatalytic composite paper for degradation of organic dyes. [ABSTRACT FROM AUTHOR]