Electronic Supplementary Information for

Biomass polymer-assisted fabrication of aerogel from MXene with ultrahigh compression elasticity and pressure sensitivityYijie Hu1, Hao Zhuo1, Qingsong Luo1, Yaxiao Wu1, Rui Wen1, Zehong Chen1, Linxiang Liu1, Linxin Zhong*1, and Xinwen Peng*1, Runcang Sun2

1.State Key Laboratory of Pulp and Paper Engineering, South China University of

Technology, Guangzhou, P. R. China. 2. Centre for Lignocellulose Science and Engineering and Liaoning Key Laboratory Pulp

and Paper Engineering, Dalian Polytechnic University, Dalian 116034, China.

*Corresponding authors. E-mail: lxzhong0611@scut.edu.cn (L. Zhong) and

fexwpeng@scut.edu.cn (X. Peng).

Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A.This journal is © The Royal Society of Chemistry 2019

Fig. S1. SEM images of Ti3AlC2 precursor (MAX).

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Fig. S2. Atomic force microscope (AFM) image of MXene sheet and its thickness.

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Fig. S3. Tyndall effect of freshly prepared Ti3C2 colloid solution, indicating its great

suspensibility.

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Fig. S4. Pictures of the as-prepared aerogels and corresponding carbon aerogels. a) Pictures of

MXene, CS1/MXene, CS5/MXene, CS10/MXene, and CS aerogels, from left to right. b) Pictures of MXene-C,

CS1/MXene-C, CS5/MXene-C, CS10/MXene-C, and CS-C carbon aerogels, from left to right.

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Fig. S5. Densities of CS-C and CSx/MXene-C carbon aerogels. The density decreases with increasing

MXene content.

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Fig. S6. Morphologies of CS, CS-C, CSx/MXene, and CSx/MXene-C. a) SEM image of CS. b) SEM image of

CS-C. c) SEM image of CS1/MXene. d) SEM image of CS1/MXene-C. e) SEM image of CS10/MXene. f) SEM image

of CS10/MXene-C. All of the aerogels show oriented lamella structures, and the structures well-

reserved after annealing.

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Fig. S7. SEM image of carbonized MXene sheets (annealing MXene sheets on AAO template at 800°C

under Ar2).

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Fig. S8. EDS elemental mappings of CS5/MXene-C.

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Fig. S9. Illustration of the directional freeze-casting strategy.

ΔTΔT

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Fig. S10. SEM images of a) R-CS5/MXene and b) R-CS5/MXene-C (fabricated via random freeze-casting).

Both of them show disordered structures.

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Fig. S11. XRD and Raman patterns of as-prepared samples. a) XRD patterns of MXene, MXene-C, CS-C,

and CSx/MXene-C. MXene presents a strong peak at 2θ=5.9°. The characteristic peaks of TiO2 (marked

with asterisks) are obvious in the patterns of MXene-C and CSx/MXene-C, suggesting the oxidation of

MXene. b) Raman spectra of MXene, MXene-C, CS-C, and CSx/MXene-C, which exhibit D band (1340 cm-1,

attributed to the defects or disorders of carbon) and G band (1600 cm-1, represent ordered graphitic

structure), respecitvely.

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Fig. S12. Compressibility and elasticity of MXene, CSX/MXene aerogels, and CS. a) Stress-strain plot

of MXene aerogel, which shows no elasticity and collapse at 70% strain. b) Stress-strain plot of

CS1/MXene. c) Stress-strain plot of CS5/MXene. d) Stress-strain plot of CS10/MXene. All of the

CSX/MXene aerogels show elasticity in a certain degree. e) Stress-strain plot of CS, which exhibits

an obvious height loss.

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Fig. S13. Stress-strain plot of CS-C. The carbon aerogel shows height loss and sever structural

damage after 100 cycles at 70% strain.

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Fig. S14. Elasticity of R-CS5/MXene-C. a) Stress-strain plot of R-CS5/MXene-C, which shows

significant stress and height loss after 10 compression cycles under 70% strain. b) SEM images of R-

CS5/MXene-C after 10 compression cycles at 70% strain, which reveals a sever deformation under

compression.

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Fig. S15. SEM images of CS-C before and after cyclic compression at 50% strain. a) Original

structure of CS-C. b) Structure of CS-C after 500 cycles, which reveals a sever deformation under

compression.

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Fig. S16. The relationship among strain, pressure, and ΔI/I0 of CS5/MXene-C.

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Fig. S17. Stability performance of CS5/MXene-C-based sensor within 10 000 compression cycles.

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Fig. S18. Nonlinear sensitivity of R-CS5/MXene-C.

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Fig. S19. Gauge factor of CS5/MXene-C-based sensor at strain of less than 5.5%.

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Fig. S20. Repeatable bendability of carbon aerogel.

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Fig. S21. Bending angle detection of CS5/MXene-C.

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Fig. S22. Assembly of CS5/MXene-C-based sensing system and mechanism.