Remarkable photochemical HER activity of semiconducting 2H
$$\hbox {MoSe}_{{2}}$$
MoSe
2
and
$$\hbox {MoS}_{{2}}$$
MoS
2
covalently linked to layers of 2D structures and of the stable metallic 1T phases prepared solvo- or hydro-thermally
$$^{\S }$$
ยง