Mechanisms of Laser Ablation in Liquids and Their Impact on the Efficiency of Nanoparticle Generation

Laser ablation in liquid is a versatile and environmentally friendly method for producing nanoparticles from a wide range of materials. While recent advances have significantly increased productivity, laser ablation in liquid remains less energy‐efficient than ablation in air. Simulations have suggested that this discrepancy arises from the redeposition of ablated material, but experimental validation has so far been lacking. Here, we quantify the energy efficiency of laser ablation in liquid and provide direct experimental verification of redeposition. An absorption‐corrected one‐to‐one comparison of single‐pulse ablation in air and water shows that the absorption‐corrected specific energy for ablation increases fourfold in water due to redeposition, from 50 J mm −3 to 200 J mm −3 . For multi‐pulse conditions, the required energy for ablation based on the incident pulse energy amounts to 431 J mm −3 , corresponding to an order‐of‐magnitude improvement compared to the best ultrafast LAL value of 3333 J mm −3 reported to date. These findings establish the practical potential of LAL for green and energy‐efficient nanoparticle synthesis.