The Royal Navy by tradition has had Chinese laundrymen on their ships so yes the Chinese were involved in WW1
A coin from the last days of the Ottoman Empire: Turkey 20 Kurush (Piastres) AH 1327 (AD 1909) Regnal Year 9 (AD 1917) Silver, 37 mm, 23.85 gm El Ghazi at right of Toughra (Sultan's signature)
This could be interesting! A lot of WWI era coin pictures here. I see several categories of coins. Coins issued by countries at war and coins of the neutrals. Coins of occupied nations issued by their occupiers. Coins issued in war time base metals like zinc and others still in high grade silver. Coins of surviving governments which remained in circulation for decades after the war ended.