Solidity Smart Contracts: Sending BNB on Ethereum and Deploying on the Binance Smart Chain

4 min readFeb 22, 2023

Solidity is a popular programming language used for developing smart contracts on the Ethereum network. Smart contracts are self-executing contracts that are tamper-proof and irreversible, making them ideal for implementing financial transactions and agreements. In this article, we will explore how to develop a Solidity smart contract that can be used for sending BNB coins on the Ethereum network, charge gas fees, and then deploy it on the Binance Smart Chain.

Developing a Solidity Smart Contract for Sending BNB Coins

The first step in developing a Solidity smart contract for sending BNB coins is to import the ERC-20 standard interface, which is used for managing tokens. We will also define our contract and declare our state variables, which will include the sender’s address, the recipient’s address, and the amount of BNB to be sent.

pragma solidity ^0.8.0;

interface IERC20 {
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
}

contract BNBSender {
    address public sender;
    address public recipient;
    uint256 public amount;

    constructor(address _recipient, uint256 _amount) {
        sender = msg.sender;
        recipient = _recipient;
        amount = _amount;
    }

    function send() external returns (bool) {
        IERC20 BNB = IERC20(0xB8c77482e45F1F44dE1745F52C74426C631bDD52);
        BNB.transferFrom(sender, recipient, amount);
        return true;
    }
}

In this code, we have defined our smart contract BNBSender and declared our state variables sender, recipient, and amount. We have also imported the ERC-20 interface and created a send() function that transfers BNB from the sender to the recipient using the transferFrom() function of the Binance Coin (BNB) token contract.

Deploying the Smart Contract on the Binance Smart Chain

To deploy our Solidity smart contract on the Binance Smart Chain, we will first need to switch our MetaMask wallet to the Binance Smart Chain network. We will then need to compile and deploy our contract using the Remix IDE.

To deploy the contract, we will first need to compile it by selecting the Solidity compiler and setting the version. Once the contract has been compiled, we can deploy it by selecting the Binance Smart Chain network and then selecting the "Create" button.

Once the contract has been deployed, we can interact with it by entering the recipient address and the amount of BNB we wish to send in the “send” function. We will then need to confirm the transaction and pay the gas fees in BNB to complete the transaction.

Charging Gas Fees on Ethereum Network

Every transaction that occurs on the Ethereum network requires gas, which is a fee paid by the transaction sender to the network to incentivize miners to validate and execute the transaction. In order to charge gas fees in our Solidity smart contract, we can add a modifier that requires the transaction sender to pay a certain amount of BNB as gas fees.

pragma solidity ^0.8.0;

interface IERC20 {
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
}

contract BNBSender {
    address public sender;
    address public recipient;
    uint256 public amount;

    constructor(address _recipient, uint256 _amount) {
        sender = msg.sender;
        recipient = _recipient;
        amount = _amount;
    }

    modifier paysGasFee() {
        IERC20 BNB = IERC20(0xB8c77482e45F1F44dE1745F52C74426C631bDD52);
        uint256 gasPrice = tx.gasprice;
        uint256 gasUsed = tx.gasprice * 21000;
        uint256 gasCost = gasPrice * gasUsed;
        require(BNB.transferFrom(msg.sender, address(this), gasCost), "Gas fee payment failed");
        _;
    }

    function send() external paysGasFee returns (bool) {
        IERC20 BNB = IERC20(0xB8c77482e45F1F44dE1745F52C74426C631bDD52);
        BNB.transferFrom(sender, recipient, amount);
        return true;
    }
}

In this code, we have added a paysGasFee() modifier that calculates the gas fee based on the gas price and the amount of gas used. We then require the transaction sender to transfer the calculated gas fee to our contract using the transferFrom() function of the Binance Coin (BNB) token contract.

Deploying the Smart Contract on the Binance Smart Chain

Conclusion

In this article, we have explored how to develop a Solidity smart contract that can be used for sending BNB coins on the Ethereum network, charge gas fees, and then deploy it on the Binance Smart Chain. Solidity is a powerful programming language that is used for developing smart contracts on the Ethereum network and is rapidly gaining popularity in the blockchain community. By understanding how to develop Solidity smart contracts, you can leverage the power of blockchain technology to create decentralized applications that are transparent, secure, and tamper-proof.