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Nimble pH response nanocomposite hydrogels (NC gel) with ultrahigh tensibility and high transparency were synthesized via in situ copolymerization of acrylamide and sodium acrylate (SA) in the aqueous suspension of hectorite clay Laponite RDS with a minute amount of N,N′-methylenebisacrylamide (BIS). The stability of the Laponite suspension containing ionic monomers and the tensile properties of the NC gels were investigated. The addition of ionic monomer SA was found to reduce the ζ potential and stability of the suspension. The tensile strength and elongation at break of these ionic NC gels obviously decreased when SA was greater than 10 mol % in the monomers. Interestingly, the addition of a minute amount of BIS (≤0.05 mol %) enhanced the homogeneity of the ionic NC gels and thus improved their transparency (transmittance >90%), tensile strength (>100 kPa), and elongation (>2000%). The relaxation modulus of the ionic NC gels was fit with G(t) = G e[1 + (t/λ0)−n ], where G e was the equilibrium modulus and λ0 was a material-dependent time constant. The relaxation exponent, n, for the ionic NC gels was 0.10 to 0.18, which is similar to that of the lightly cross-linked nature rubber. This moderate relaxation observed was considered to be the origin of the ultrahigh tensibility of the ionic NC gels. Fortunately, the nimble pH response still remained in the present NC gels containing carboxyl groups. The oscillatory swelling−shrinking circles switched by pH at 7.4 and 3.0 were observed from the present NC gels.

The plasmonic characteristic of core–shell nanomaterials can effectively improve exciton‐generation/dissociation and carrier‐transfer/collection. In this work, a new strategy based on core–shell Au@CdS nanospheres is introduced to passivate perovskite grain boundaries (GBs) and the perovskite/hole transport layer interface via an antisolvent process. These core–shell Au@CdS nanoparticles can trigger heterogeneous nucleation of the perovskite precursor for high‐quality perovskite films through the formation of the intermediate Au@CdS–PbI2 adduct, which can lower the valence band maximum of the 2,2,7,7‐tetrakis(N,N‐di‐p‐methoxyphenyl‐amine)9,9‐spirobifluorene (Spiro‐OMeTAD) for a more favorable energy alignment with the perovskite material. With the help of the localized surface plasmon resonance effect of Au@CdS, holes can easily overcome the barrier at the perovskite/Spiro‐OMeTAD interface (or GBs) through the bridge of the intermediate Au@CdS–PbI2, avoiding the carrier accumulation, and suppress the carrier trap recombination at the Spiro‐OMeTAD/perovskite interface. Consequently, the Au@CdS‐based perovskite solar cell device achieves a high efficiency of over 21%, with excellent stability of ≈90% retention of initial power conversion efficiencies after 45 days storage in dry air.

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