There is a lack of straightforward methods to prepare high‐quality bismuthene nanosheets, or, even more challengingly, to grow their arrays due to the low melting point and high oxophilicity of bismuth. This synthetic obstacle has hindered their potential applications. In this work, it is demonstrated that the galvanic replacement reaction can do the trick. Under well‐controlled conditions, large‐area vertically aligned bismuthene nanosheet arrays are grown on Cu substrates of various shapes and sizes. The product features small nanosheet thickness of two to three atomic layers, large surface areas, and abundant porosity between nanosheets. Most remarkably, bismuthene nanosheet arrays grown on Cu foam can enable efficient CO2 reduction to formate with high Faradaic efficiency of >90%, large current density of 50 mA cm−2, and great stability.

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In this article, flake graphite, nitric acid, peroxyacetic acid and phosphoric acid are used to prepare graphene oxide phosphonic and phosphinic acids (GOPAs), and GOPAs and polyvinyl alcohol (PVA) are used to synthesize polyvinyl alcohol graphene oxide phosphonate and phosphinate (PVAGOPs) in the case of faint acidity and ultrasound irradiation, and PVAGOPs are used to fabricate PVAGOPs film, and the structure and morphology of GOPAs, PVAGOPs and PVAGOPs film are characterized, and the thermal stability and mechanical properties of PVAGOPs film are investigated. Based on these, it has been proved that GOPAs consist of graphene oxide phosphonic acid and graphene oxide phosphinic acid, and there are CP covalent bonds between them, and PVAGOPs are composed of GOPAs and PVA, and there are six-member lactone rings between GOPAs and PVA, and the thermal stability and mechanical properties of PVAGOPs film are improved effectively.

In this paper, polyvinyl alcohol/phytic acid polymer (PVA/PA polymer) was synthesized through esterification reaction of PVA and PA in the case of acidity and ultrasound irradiation and characterized, and PVA/PA polymer film was prepared by PVA/PA polymer and characterized, and the influence of dosage of PA on the thermal stability, mechanical properties and surface resistivity of PVA/PA polymer film were researched, and the influence of sonication time on the mechanical properties of PVA/PA polymer film was investigated. Based on those, it was concluded that the hydroxyl group on the chain of PVA and the phosphonic group on PA were connected together in the form of phosphonate bond, and the hydroxyl group on the chain of PVA were connected together in the form of ether bond after the intermolecular dehydration; in the meantime, it was also confirmed that PVA/PA polymer film prepared from 1.20mL of PA not only had the high thermal stability and favorable ductility but also the low surface resistivity in comparison with PVA/PA polymer film with 0.00mL of PA, and the ductility of PVA/PA polymer film was very sensitive to the sonication time.

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