摘要
Two-dimensional porous nanosheet heterostructure materials,which combine the advantages of both architecture and components,are expected to feature a significant photocatalytic performance toward CO_(2) conversion into useful fuels.Herein,we provide a facile strategy for fabricating sulfur-doped C_(3)N_(4) porous nanosheets with embedded SnO_(2)-SnS_(2) nanojunctions(S-C_(3)N_(4)/SnO_(2)-SnS_(2))via liquid impregnation-pyrolysis and subsequent sulfidation treatment using a layered supramolecular structure as the precursor of C_(3)N_(4).A hexagonal layered supramolecular structure was first prepared as the precursor of C_(3)N_(4).Then Sn^(4+) ions were intercalated into the supramolecular interlayers through the liquid impregnation method.The subsequent annealing treatment in air simultaneously realized the fabrication and efficient exfoliation of layered C_(3)N_(4) porous nanosheets.Moreover,SnO_(2) nanoparticles were formed and embedded in situ in the porous C_(3)N_(4) nanosheets.In the following sulfidation process under a nitrogen atmosphere,sulfur powder can react with SnO_(2) nanoparticles to form SnO_(2)-SnS_(2) nanojunctions.As expected,the exfoliation of sulfur-doped C_(3)N_(4) porous nanosheets and ternary heterostructure construction could be simultaneously achieved in this work.Sulfur-doped C_(3)N_(4) porous nanosheets with embedded SnO_(2)-SnS_(2) nanojunctions featured abundant active sites,enhanced visible light absorption,and efficient interfacial charge transfer.As expected,the optimized S-C_(3)N_(4)/SnO_(2)-SnS_(2) achieved a much higher gas-phase photocatalytic CO_(2) reduction performance with high yields of CO(21.68μmol g^(−1)h^(−1))and CH_(4)(22.09μmol g^(−1)h^(−1))compared with the control C_(3)N_(4),C_(3)N_(4)/SnO_(2),and S-C_(3)N_(4)/SnS_(2) photocatalysts.The selectivity of CH_(4) reached 80.30%.Such a promising synthetic strategy can be expected to inspire the design of other robust C_(3)N_(4)-based porous nanosheet heterostructures for a broad range of applications.
结合了多孔纳米片和异质结优点的二维多孔纳米片异质结构材料预计能在CO_(2)光催化还原为燃料过程中表现出优异的性能.本文中,我们提出了一种简便的合成方案,即通过液体浸渍-热解和后续的硫化处理,将层状结构的超分子前驱体转变成C_(3)N_(4),形成了硫掺杂的原位嵌入的SnO_(2)-SnS_(2)纳米异质结C_(3)N_(4)多孔纳米片(S-C_(3)N_(4)/SnO_(2)-SnS_(2)).在这项研究中,硫掺杂的C_(3)N_(4)多孔纳米片的剥离和SnO_(2)-SnS_(2)纳米异质结同时获得.SnO_(2)-SnS_(2)纳米异质结的硫掺杂C_(3)N_(4)多孔纳米片具有丰富的活性位点、增强的可见光吸收能力和界面电荷转移效率.正如预期,与C_(3)N_(4),C_(3)N_(4)/SnO_(2)和S-C_(3)N_(4)/SnS_(2)光催化剂相比,优化的S-C_(3)N_(4)/SnO_(2)-SnS_(2)具有更高的气相光催化还原CO_(2)性能,CO产率(21.68μmol g^(−1)h^(−1))和CH_(4)产率(22.09μmol g^(−1)h^(−1))显著提高.CH_(4)的选择性可达80.30%.这种合成策略有望推动其他C_(3)N_(4)基多孔纳米片异质结构的研究,以实现更广泛的应用.
基金
supported by the National Natural Science Foundation of China(22072037 and 51772079)
the Natural Science Foundation of Heilongjiang Province of China(LH2020B018)。
