Research / 2021 / Article / Fig 4

Research Article

Liquid Metal-Based Epidermal Flexible Sensor for Wireless Breath Monitoring and Diagnosis Enabled by Highly Sensitive SnS2 Nanosheets

Figure 4

Theoretical interpretations based on first-principle calculations. (a) Optimized target gas molecules are adsorbed onto the SnS2 supercell. Calculated (b) molecular surface adsorption energies and (c) charge transfer. (d) Charge density difference between NO and H2O molecules after being adsorbed onto SnS2, where the red and blue regions represent electron loss and gain, respectively. (e) Raman spectrum of SnS2 before and after adsorbing NO gas and (f) the corresponding intensity ratio of A1g and Eg modes. (g) Calculated deformation along the - and -directions of the A1g and Eg modes. (h) The seven chosen S atoms (S atom no. 3 is the NO adsorption site) and the positional change of the seven S atoms in the (i) - and (j) -directions after NO adsorption.