Some information regarding him can be found here (scroll down a little). There is much more here, but little is said regarding his career as a painter.
It seems that a 1910 exhibit of Gustav Klimt paintings inspired him, though he surely was aware of Art Nouveau artists such as Aubrey Beardsley, echoes of whose work might be detected.
Zecchin's most noteworthy paintings were a set of murals for a Lido hotel that was destroyed -- though much or all of the art remains. The theme of the murals was the Thousand and One Nights, a work very popular around 1914 when the murals were completed.
Below are some examples of Zecchin's paintings, including a few iPhone snapshots I took at Venice's Ca' Pesaro museum.