Related party transactions (Details 2) - 6 months ended Mar. 31, 2026 - Lease No 1 [Member] - Zhejiang Tantech Bamboo Technology Co., Limited [Member] |
CNY (¥)
ft²
|
USD ($)
ft²
|
|---|---|---|
| RMB [Member] | ||
| Annual rent RMB | ¥ | ¥ 131,835 | |
| Annual rent in USD | $ | $ 18,817 | |
| Lease begin date | March 1, 2023 | March 1, 2023 |
| Lease end date | February 29, 2028 | February 29, 2028 |
| Leasing purpose | Office | Office |
| Area (in square meters) | ft² | 479 | 479 |