No disposable diapers are 100% environmentally friendly because they all require resources to make, ship and then take awhile to decompose once you throw them away.
However there are some disposable baby diapers that are more environmentally friendly than others such as Seventh Generation Diapers, Honest Company Diapers, Bamboo Nature Diapers and Parents Choice Diapers.
Those would be some good diapers that are more environmentally friendly than other diapers but no diaper is 100% biodegradable.
The most environmentally friendly diapers would be cloth diapers but they require work.