Install the Noto emoji font and make this file exist:
~/.config/fontconfig/conf.d/999-emoji.conf
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE fontconfig SYSTEM "fonts.dtd"> <fontconfig> <match> <test name="family"><string>sans-serif</string></test> <edit name="family" mode="append" binding="strong"> <string>Bitstream Vera Serif</string> <string>Noto Color Emoji</string> </edit> </match> <!-- Add emoji generic family --> <alias binding="strong"> <family>emoji</family> <default><family>Noto Color Emoji</family></default> </alias> <!-- Aliases for the other emoji fonts --> <alias binding="strong"> <family>Apple Color Emoji</family> <prefer><family>Noto Color Emoji</family></prefer> </alias> <alias binding="strong"> <family>Segoe UI Emoji</family> <prefer><family>Noto Color Emoji</family></prefer> </alias> <alias binding="strong"> <family>Emoji One</family> <prefer><family>Noto Color Emoji</family></prefer> </alias> </fontconfig>