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Graphical abstract We fabricate the ultrathin and flexible four corners needle zinc oxide whiskers/silver/waterborne polyurethane (T-ZnO/Ag/WPU) conductive films to satisfy different EMI shielding demand by tuning the shielding network structure. Highlights • The specially designed 3D T-ZnO/Ag nanofiller is synthesized successfully. • The ultrathin and flexible T-ZnO/Ag/WPU EMI shielding film is fabricated. • The film with uniform structure shows an EMI SE of 42 dB at thickness of 0.02 mm. • The film with deposited layer structure exhibits an ultra-high EMI SE of 87 dB. Abstract With recent emergence of portable and wearable electronics, it is imperative to design a novel electromagnetic interference (EMI) shielding material which possesses flexibility, ultra-thinness and excellent EMI shielding effectiveness (SE) to prevent the adverse effect of electromagnetic radiation. Herein, we fabricate the ultrathin and flexible four corners needle zinc oxide whiskers/silver/waterborne polyurethane (T-ZnO/Ag/WPU) conductive films to realize different EMI shielding demand by tuning the nanofiller dispersion morphology. The T-ZnO/Ag/WPU composite film with uniform structure (prepared by blade coating method) shows excellent flexibility and EMI SE of over 42 dB at a thickness of only 0.02 mm. Highly reliable shielding ability is achieved with 92% EMI SE retention after 1000 folding cycle tests. The T-ZnO/Ag/WPU composite film with deposited layer structure (prepared by casting method) exhibits an ultrahigh EMI SE of over 87 dB at a thickness of 0.25 mm. At the same time, the T-ZnO/Ag/WPU composite shows great potential in printable circuit. The ultrathin and flexible T-ZnO/Ag/WPU composite films with excellent EMI SE are highly promising for applications in next-generation flexible electronics, especially the portable and wearable electronic devices. [ABSTRACT FROM AUTHOR]

A lightweight 3D Ag/CNTs/SBS composite foam was successfully fabricated by a simple freeze-drying process followed by adsorbing and in-situ reducing of silver trifluoroacetate in ethanol solution, which exhibited robust mechanical–electrical performance and high EMI shielding performance due to the synergistic contribution of the CNTs with ultra-high aspect ratio inside the SBS matrix and Ag NPs partially embedded in the superficial surface of the SBS foam skeleton. [Display omitted] • Lightweight Ag/CNTs/SBS foam was fabricated by freeze-drying and in-situ reduction. • CNTs and partially embedded Ag NPs endow the foam with excellent properties. • The foam exhibits high EMI SE of 91 dB at 4 mm in the X band. • The foam possesses enhanced EMI SE value after the cyclic compressions. The porous conductive polymer composites have received great attention owing to their superiority of being utilized in electromagnetic interference (EMI) shielding applications. Herein, lightweight and highly compressible conductive composite foam composed of poly(styrene- block -butadiene- block -styrene) (SBS) polymer matrix, carbon nanotubes (CNTs) and silver nanoparticles (Ag NPs) is fabricated by freeze-drying technology, silver precursor absorption and in-situ reduction process. Three-dimensional CNTs conductive network and partially embedded Ag NPs synergistically endow the foam with excellent mechanical, electrical and EMI shielding performance. The flexible 8Ag/4CNTs/10SBS composite foam with a low density of 0.42 g/cm3 exhibits moderate compressive strength of 169.2 kPa at strain of 50%, remarkable conductivity of 753 S/m, and prominent EMI shielding effectiveness (SE) value of around 91 dB in the electromagnetic wave frequency range of 8.2–12.5 GHz. In addition, the 4Ag/4CNTs/10SBS composite foam exhibits robust mechanical–electrical property upon 1000 compression-release cycles at strain of 50%, and its SE value increased by about 33% compared with the initial state after the cyclic compression test. These results suggest that the Ag/CNTs/SBS foams possess promising potential to be used as lightweight, flexible, and high-performance EMI shielding materials in modern electronic devices. [ABSTRACT FROM AUTHOR]

A lightweight 3D Ag/CNTs/SBS composite foam was successfully fabricated by a simple freeze-drying process followed by adsorbing and in-situ reducing of silver trifluoroacetate in ethanol solution, which exhibited robust mechanical–electrical performance and high EMI shielding performance due to the synergistic contribution of the CNTs with ultra-high aspect ratio inside the SBS matrix and Ag NPs partially embedded in the superficial surface of the SBS foam skeleton. [Display omitted] • Lightweight Ag/CNTs/SBS foam was fabricated by freeze-drying and in-situ reduction. • CNTs and partially embedded Ag NPs endow the foam with excellent properties. • The foam exhibits high EMI SE of 91 dB at 4 mm in the X band. • The foam possesses enhanced EMI SE value after the cyclic compressions. The porous conductive polymer composites have received great attention owing to their superiority of being utilized in electromagnetic interference (EMI) shielding applications. Herein, lightweight and highly compressible conductive composite foam composed of poly(styrene- block -butadiene- block -styrene) (SBS) polymer matrix, carbon nanotubes (CNTs) and silver nanoparticles (Ag NPs) is fabricated by freeze-drying technology, silver precursor absorption and in-situ reduction process. Three-dimensional CNTs conductive network and partially embedded Ag NPs synergistically endow the foam with excellent mechanical, electrical and EMI shielding performance. The flexible 8Ag/4CNTs/10SBS composite foam with a low density of 0.42 g/cm3 exhibits moderate compressive strength of 169.2 kPa at strain of 50%, remarkable conductivity of 753 S/m, and prominent EMI shielding effectiveness (SE) value of around 91 dB in the electromagnetic wave frequency range of 8.2–12.5 GHz. In addition, the 4Ag/4CNTs/10SBS composite foam exhibits robust mechanical–electrical property upon 1000 compression-release cycles at strain of 50%, and its SE value increased by about 33% compared with the initial state after the cyclic compression test. These results suggest that the Ag/CNTs/SBS foams possess promising potential to be used as lightweight, flexible, and high-performance EMI shielding materials in modern electronic devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ultra-soft Ag@PDMS/silicone (APS) composites were successfully fabricated. • The compression capability of APS can be regulated by a modulus matching strategy. • The APS exhibits excellent EMI shielding and near-field shielding performance. Electrically conductive silicone composites have made significant advancements in the field of electromagnetic interference (EMI) shielding due to their excellent conductivity, elasticity, sealability and environmental reliability. Notably, chips and other miniature electronic components with limited pressure-bearing capacity often require composites with both low compressive stress and high EMI shielding performance. Unfortunately, conventional conductive silicone composites often exhibit high compressive stress as a result of the high modulus and high loading contents of fillers, which prevents them from fitting perfectly with the package cavity under low package stress conditions, resulting in inadequate EMI shielding. Herein, the elastic modulus of the silver@polydimethylsiloxane (Ag@PDMS) conductive filler can be adjusted by controlling the crosslinking ratio, which enables the creation-of-Ag@PDMS/Silicone-(APS)-conductive-composites-with-remarkable compressibility, EMI shielding and sealing capabilities. The-APS-composites exhibit a compressive stress of only 0.3 MPa under 50 % compressive strain, which is essential for the packaging-of-precision electronic components. The APS composites show a significant decrease in compressive stress (54 %) and elastic modulus (80 %) under 50 % compressive strain, in comparison to conventional polymer composites with hard fillers. Meanwhile, the APS composites exhibit a-satisfactory-EMI-shielding-effectiveness-(SE)-of-71-dB and demonstrate excellent electromagnetic sealing capabilities in practical electronics. This study provides an effective approach for developing and constructing high-performance ultra-soft composites for precision electronic components packaging. [ABSTRACT FROM AUTHOR]

[Display omitted] • The first synthesis of the passivation layer via embedded p-n heterointerfaces by using a simple laser technology. • We propose a new mechanism of the embedded p-n heterointerfaces for improved carrier transfer. • The embedded p-n heterointerfaces in passivation layers lead to significantly boosted PEC performance: a 12-fold increase for the lifetime of photogenerated electrons and a 3.9-fold increase for the η inj at 1.23 V RHE. Addressing the carrier loss at the semiconductor-liquid junction of metal oxides is of significance for developing high-performance photoelectrodes for viable solar hydrogen generation, while one of the critical challenges remains in pursuing the top passivation layer with pronounced carrier extraction capability. In the present work, we propose and experimentally verify that artificial engineering of the passivation layer via laser embedding of p-n heterointerfaces leads to significantly improved carrier transfer. By virtue of the advantage of generating nanocrystals in any desired solvents via the technology of laser synthesis and processing of colloids (LSPC), p-type CdTe nanocrystals are successfully embedded in a thin layer of TiO 2 , which is adopted as an efficient passivation layer to address the excessive surface defects and the slow carrier transfer at α-Fe 2 O 3 photoanodes. The embedded p-n heterointerfaces not only provide an effective built-in electric field that accelerates carrier transport in TiO 2 via boosting polaron hopping but also activate hole transfer by shifting up the valence band in TiO 2. Such vivid embedding is demonstrated to generate a 12-fold increase for the lifetime of photogenerated electrons, and a 3.9-fold increase for the η inj at 1.23 V RHE , leading to a 4.4-fold increase in the photocurrent density at 1.23 V RHE. We thus believe the present work provides a universal alternative for regulating the chemical/physical features of semiconductor-liquid junctions at metal oxides. [ABSTRACT FROM AUTHOR]