采用一步水热法，通过In3+的掺杂，获得了尺寸可控的近红外(NIR)发光ZGO∶1.5%Cr，xIn(Zn1.4Ga1.97-2xO4∶1.5%Cr，xIn，x=0%、0.1%、0.2%、0.3%、0.4%、0.5%)长余辉纳米颗粒(PLNPs)，考察了In3+掺杂量对ZGO∶1.5%Cr，xIn PLNPs尺寸大小、余辉发光性能以及晶体结构的影响。In3+的掺杂不仅能有效控制ZGO∶1.5%Cr，xIn PLNPs尺寸，还可以增强发光和余辉时间。结果表明，当In3+掺杂量为0.2%时，ZGO∶1.5%Cr，0.2%In PLNPs平均粒径为13.79 nm，分布最为均匀，粒径最小，NIR发光最强，余辉时间超过5 d，可通过LED灯再激发。In3+的掺杂对ZGO∶1.5%Cr，xIn PLNPs的晶体结构无影响，均为纯相的尖晶石结构。
Constructing a CeO2/ZnxCd1−xIn2S4 S-Scheme Hollow Heterostructure for Efficient Photocatalytic H2 Evolution
With the exhaustion of fossil energy, the energy crisis is becoming increasingly serious, which greatly hinders the sustainable development of society. Therefore, the development of new energy technologies as a substitute for non-renewable and highly polluting fossil energy is extremely urgent. The environmental benefits and high energy density of hydrogen (H2) make it an ideal clean energy source. Photocatalytic water splitting, which was first demonstrated in the pioneering work on TiO2 photoelectrodes under UV-light irradiation, has been extensively researched and has been shown to be an effective method for addressing the global energy crisis. However, most of the photocatalysts used for H2 production still suffer from low solar energy utilization and fast photogenerated charge recombination, which seriously limit their practical applications in the field of solar-to-hydrogen energy conversion. Therefore, it is necessary yet greatly challenging to develop a visible-light-responsive photocatalyst with efficient photogenerated charge separation through reasonable modification strategy. Layered structured ZnIn2S4 (ZIS) is a promising photocatalyst to split water for H2 evolution owing to its suitable electronic structure, strong light absorption, chemical stability, and low toxicity. However, its low charge separation efficiency renders its photocatalytic performance unsatisfactory. Herein, to overcome this issue, a band structure regulation strategy that integrates solid solution formation with heterostructure construction was proposed. By growing ZnxCd1−xIn2S4 (ZCIS) nanosheets on the surface of CeO2 hollow spheres in situ, a novel hollow heterostructure CeO2/ZCIS with efficient charge separation was constructed as photocatalyst for H2 generation. The introduction of the Cd cation in ZIS upshifts the conduction band (CB) and valence band (VB) of ZCIS, enhancing the built-in electrical field on the interface. Those electronic band changes induce the S-scheme structure in CeO2/ZCIS, promoting charge separation for photocatalysis. Moreover, the upshift of the CB generates photoelectrons with high H2 generation ability. As a result, the optimal 1:6-CeO2/Zn0.9Cd0.1In2S4 heterostructure exhibits 4.09 mmol·g−1·h−1 H2 generation during photocatalysis, which is 6.8-, 3.0-, and 2.2-fold as those of ZIS, ZCIS, and CeO2/ZIS, respectively. This work provides one efficient strategy to develop highly active S-scheme photocatalysts for hydrogen generation.