Reduced-graphene-oxide (rGO) aerogels provide highly stabilising, multifunctional, porous supports for hydrotalcite-derived nanoparticles, such as MgAl-mixed-metal-oxides (MgAl-MMO), in two commercially important sorption applications. Aerogel-supported MgAl-MMO nanoparticles show remarkable enhancements in adsorptive desulfurization performance compared to unsupported nanoparticle powders, including substantial increases in organosulfur uptake capacity (>100% increase), sorption kinetics (>30-fold), and nanoparticle regeneration stability (>3 times). Enhancements in organosulfur capacity are also observed for aerogelsupported NiAl-and CuAl-metal-nanoparticles. Importantly, the electrical conductivity of the rGO aerogel network adds completely new functionality by enabling accurate and stable nanoparticle temperature control via direct electrical heating of the graphitic support. Support-mediated resistive heating allows for thermal nanoparticle recycling at much faster heating rates (>700 °C•min −1) and substantially reduced energy consumption, compared to conventional, external heating. For the first time, the CO 2 adsorption performance of MgAl-MMO/rGO hybrid aerogels is assessed under elevated-temperature and high-CO 2-pressure conditions relevant for pre-combustion carbon capture and hydrogen generation technologies. The total CO 2 capacity of the aerogel-supported MgAl-MMO nanoparticles is more than double that of the unsupported nanoparticles and reaches 2.36 mmol•CO 2 g −1 ads (at p CO2 = 8 bar, T = 300 °C), outperforming other high-pressure CO 2 adsorbents.

Porous boron nitride particles were embedded within carbon nanotube aerogels to produce electrically-conducting sorbents that combine remarkable desulfurisation performance with the capability for rapid, energy-efficient Joule-heating regeneration.

Nanocarbon aerogels display outstanding electrical and solar-thermal heating efficiencies. However, little is known about the relationship between their microstructure and the heating performance. In this study, two different types of carbon nanotube (CNT) aerogels were synthesized via an ice-templating (IT) and emulsion-templating (ET) approach, respectively, which induces drastic difference in internal microstructures, crosslinking densities and porosities. These structural differences give rise to substantial efficiency differences in electrical aerogel heating (e.g. 46 o C/W for rET-CNT aerogel, 75 o C/W for rIT-CNT aerogel). Systematic comparison of nanocarbon aerogel microstructure in terms of nanocarbon type, envelope density, and nanocarbon graphiticity shows that the Joule-heating efficiency is highly correlated with the thermal conductivities of the aerogels, where aerogels with lower thermal conductivities exhibit higher Joule-heating efficiencies. This relationship is also observed for solar-thermal aerogel heating, with the aerogels of lowest thermal conductivity (rIT-CNT aerogel) exhibiting a 30% higher efficiency in solar water evaporation, compared to rET-CNT aerogels. These results demonstrate that the heating properties of nanocarbon aerogels can be readily tuned and enhanced through structural control alone. The findings provide a new perspective for the design of nanocarbon aerogel for applications that involve electrical or solar-thermal heating, such as temperature-dependent separation, sorption, sensing, and catalysis.

Joule heating studies on nanoparticle/nanocarbon hybrid aerogels have been reported, but systematic investigations on hydrotalcite-derived catalysts supported onto reduced graphene oxide (rGO) aerogels are rare. In this study, hydrotalcite-derived Cu-Al2O3 nanoparticles were incorporated into a porous and multifunctional rGO aerogel support for fabricating electrically conducting Cu-Al2O3/rGO hybrid aerogels, and their properties were investigated in detail. The hybridization of Cu-Al2O3 with a 3D nanocarbon support network imparts additional functionalities to the widely used functional inorganic nanoparticles, such as direct electrical framework heating and easy regeneration and separation of spent nanoparticles, with well-spaced nanoparticle segregation. 3D variable-range hopping model fitting confirmed that electrons were able to reach the entire aerogel to enable uniform resistive heating. The conductivity of the nanocarbon support framework facilitates uniform and fast heating (up to 636 K/min) of the embedded nanoparticles at very low energy consumption, while the large porosity and high thermal conductivity enable efficient heat dissipation during natural cooling (up to 336 K/min). The thermal stability of the hybrid aerogel was demonstrated by repeated heating/cooling cycling at different temperatures that were relevant to important industrial applications. The facile synthetic approach can be easily adapted to fabricate other types of multifunctional nanoparticle/nanocarbon hybrid aerogels, such as the MgAl-MMO/rGO aerogel and the Ni-Al2O3/rGO aerogel. These findings open up new routes to the functionalization of inorganic nanoparticles and extend their application ranges that involve electrical/thermal heating, temperature-dependent catalysis, sorption, and sensing.

New approaches for the engineering of the 3D microstructure, pore modality, and chemical functionality of hierarchically porous nanocarbon assemblies are key to develop the next generation of functional aerogel and membrane materials. Here, interfacially driven assembly of carbon nanotubes (CNT) is exploited to fabricate structurally directed aerogels with highly controlled internal architectures, composed of pseudo‐monolayer, CNT microcages. CNT Pickering emulsions enable engineering at fundamentally different length scales, whereby the microporosity, mesoporosity, and macroporosity are decoupled and individually controlled through CNT type, CNT number density, and process energy, respectively. In addition, metal nanocatalysts (Cu, Pd, and Ru) are embedded within the architectures through an elegant sublimation and shock‐decomposition approach; introducing the first approach that enables through‐volume functionalization of intricate, pre‐designed aerogels without microstructural degradation. Catalytic structure–function relationships are explored in a pharma‐important amidation reaction; providing insights on how the engineered frameworks enhance catalyst activity. A sophisticated array of advanced tomographic, spectroscopic, and microscopic techniques reveal an intricate 3D assembly of CNT building‐blocks and their influence on the functional properties of the enhanced nanocatalysts. These advances set a basis to modulate structure and chemistry of functional aerogel materials independently in a controlled fashion for a variety of applications, including energy conversion and storage, smart electronics, and (electro)catalysis.