The phrase "put much effort" is correct and usable in written English.
For example, "She put much effort into her job search and eventually found the perfect position."
He didn't seem to put much effort into studying.
"He didn't put much effort in — that's not him," Velazquez said.
In truth, local governments have put much effort into maintaining this natural monopoly.
You don't have to put much effort in compared with a traditional cigarette".
"I'm better at breathing in; I don't put much effort into breathing out," he said.
"To take one example, how many American universities are going to put much effort into cassava?
America's Department of Commerce has put much effort in recent years into improving the quality of its trade numbers.
Only in the past few days, egged on by France, did American diplomats put much effort into brokering a deal.
She may have wanted to let Rupert P go, but she didn't really put much effort into doing that.
It didn't put much effort into its stores or multichannel systems to bring the online and store channels together.
He would put much effort into exploiting Scotland's renewable energy potential and into improving the scientific skills shortage.
