DHT11 sensor works on Arduino Uno, not on LoLin NodeMcu
The datasheet says 3V-5V. 3V is the minimum so I DOUBT that isn't the problem, BUT try to pump more juice into it to see what happens. Never believe the datasheet if these cheap components at 100%.

It does say this though:


  VDD=5V, T = 25℃ (unless otherwise stated)


So maybe....

Link to datasheet.